How to Configure Postfix and Dovecot with Virtual Domain Users in Linux – Part 2

In the previous article of this series we explained how to set up and manage the mail server database securely using phpMyAdmin.

Requirement:

  1. Install Postfix Mail Server and Dovecot with MariaDB – Part 1
Configure Postfix and Dovecot with Virtual Domain Users
Configure Postfix and Dovecot with Virtual Domain Users – Part 2

Now it’s time to configure the internal programs that will make sending and receiving emails a reality: Postfix and Dovecot (to handle outgoing and incoming emails, respectively).

Configuring Postfix Mail Server

Before you begin configuring Postfix, it would be worth and well to take a look at its man pages here, putting special emphasis on the section titled “Information for new Postfix users“. If you do, you will find it easier to follow along with this tutorial.

In few words, you should know that there are two configuration files for Postfix:

  1. /etc/postfix/main.cf (Postfix configuration parameters, refer to man 5 postconf for more details).
  2. /etc/postfix/master.cf (Postfix master daemon configuraton, see man 5 master for further details).

In /etc/postfix/main.cf, locate (or add, if necessary) the following lines and make sure they match the values indicated below:

main.cf
append_dot_mydomain = no
biff = no
config_directory = /etc/postfix
dovecot_destination_recipient_limit = 1
message_size_limit = 4194304
readme_directory = no
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
smtpd_banner = $myhostname ESMTP $mail_name (CentOS)
smtpd_tls_cert_file = /etc/pki/dovecot/certs/dovecot.pem
smtpd_tls_key_file = /etc/pki/dovecot/private/dovecot.pem
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtpd_use_tls = yes
virtual_transport = dovecot
smtpd_sasl_type = dovecot
smtpd_sasl_path = private/auth

The next three settings are of special importance. In the files indicated in yellow we will configure Postfix’s access to the Domains_tbl, Users_tbl, and Alias_tbl tables:

virtual_mailbox_domains = mysql:/etc/postfix/mariadb-vdomains.cf
virtual_mailbox_maps = mysql:/etc/postfix/mariadb-vusers.cf
virtual_alias_maps = mysql:/etc/postfix/mariadb-valias.cf

Note that you can choose different file names above, as long as you make sure to create them and insert the following contents in them. In each case, replace YourPassword with the password you chose for the dba user in Part 1, or you can also use the MariaDB root credentials for user and password below.

Also, make sure you use the exact same names of the email server database and tables created in Part 1.

In /etc/postfix/mariadb-vdomains.cf:

mariadb-vdomains.cf
user = dba
password = YourPassword
hosts = 127.0.0.1
dbname = EmailServer_db
query = SELECT 1 FROM Domains_tbl WHERE DomainName='%s'

In /etc/postfix/mariadb-vusers.cf:

mariadb-vusers.cf
user = dba
password = YourPassword
hosts = 127.0.0.1
dbname = EmailServer_db
query = SELECT 1 FROM Users_tbl WHERE Email='%s'

In /etc/postfix/mariadb-valias.cf:

mariadb-valias.cf
user = dba
password = YourPassword
hosts = 127.0.0.1
dbname = EmailServer_db
query = SELECT Destination FROM Alias_tbl WHERE Source='%s'

Finally, don’t forget to change the permissions to these files to 640:

# chmod 640 /etc/postfix/mariadb-vdomains.cf
# chmod 640 /etc/postfix/mariadb-vusers.cf
# chmod 640 /etc/postfix/mariadb-valias.cf

And the ownership to user root and group postfix:

# chown root:postfix /etc/postfix/mariadb-vdomains.cf
# chown root:postfix /etc/postfix/mariadb-vusers.cf
# chown root:postfix /etc/postfix/mariadb-valias.cf

Next, to enable secure connections we need to make sure the following settings are uncommented (or added, if necessary) in /etc/postfix/master.cf:

master.cf
submission inet n       -       n       -       -       smtpd
  -o syslog_name=postfix/submission
  -o smtpd_tls_security_level=encrypt
  -o smtpd_sasl_auth_enable=yes
  -o smtpd_reject_unlisted_recipient=no
  -o smtpd_recipient_restrictions=permit_sasl_authenticated,reject
  -o milter_macro_daemon_name=ORIGINATING
pickup    unix  n       -       n       60      1       pickup
cleanup   unix  n       -       n       -       0       cleanup
qmgr      unix  n       -       n       300     1       qmgr
tlsmgr    unix  -       -       n       1000?   1       tlsmgr
rewrite   unix  -       -       n       -       -       trivial-rewrite
bounce    unix  -       -       n       -       0       bounce
defer     unix  -       -       n       -       0       bounce
trace     unix  -       -       n       -       0       bounce
verify    unix  -       -       n       -       1       verify
flush     unix  n       -       n       1000?   0       flush
proxymap  unix  -       -       n       -       -       proxymap
proxywrite unix -       -       n       -       1       proxymap
smtp      unix  -       -       n       -       -       smtp
relay     unix  -       -       n       -       -       smtp

showq     unix  n       -       n       -       -       showq
error     unix  -       -       n       -       -       error
retry     unix  -       -       n       -       -       error
discard   unix  -       -       n       -       -       discard
local     unix  -       n       n       -       -       local
#virtual   unix  -       n       n       -       -       virtual
lmtp      unix  -       -       n       -       -       lmtp
anvil     unix  -       -       n       -       1       anvil
scache    unix  -       -       n       -       1       scache

Note: The indentation in the lines beginning with the -o option is critical; otherwise postfix check will return an error:

Check Postfix Configuration
Check Postfix Configuration

Before you save changes, add the following lines at the bottom of the file:

master.cf
dovecot   unix  -       n       n       -       -       pipe
    flags=DRhu user=vmail:vmail argv=/usr/libexec/dovecot/deliver -f ${sender} -d ${recipient}

At this point it is essential to check whether Postfix has access to the database tables and the domains, accounts, and alias that we created in Part 1.

To do so, we will use the postmap command, an utility to test communication with the tables Postfix will look up during operation, but first and foremost we’ll need to restart postfix:

# systemctl postfix restart
# postmap -q linuxnewz.com mysql:/etc/postfix/mariadb-vdomains.cf
# postmap -q someotherdomain.com mysql:/etc/postfix/mariadb-vdomains.cf
# postmap -q [email protected] mysql:/etc/postfix/mariadb-vusers.cf
# postmap -q [email protected] mysql:/etc/postfix/mariadb-vusers.cf
# postmap -q [email protected] mysql:/etc/postfix/mariadb-vusers.cf
# postmap -q [email protected] mysql:/etc/postfix/mariadb-valias.cf

In the image below we can see that for existing records in the database, a 1 is returned. Otherwise, nothing is displayed back to the screen. In the case of the alias check, note that the actual email account the alias is mapped to is returned:

Check Postfix Table Communication
Check Postfix Table Communication

Note that we are NOT authenticating against the credentials set for each email account, we are only testing the ability of Postfix to detect those records in the database.

Thus, if you get a different output than above, make sure you are using a valid user / password pair in mariadb-vdomains.cf, mariadb-vusers.cf, and mariadb-valias.cf (or whatever you chose to call those files).

Configuring Dovecot

As an IMAP / POP3 server, Dovecot provides a way for users through a Mail User Agent (MUA, or also known as client), such as Thunderbird or Outlook, to name a few examples to access their mail.

To begin, let’s create a user and a group to handle emails (we will need this as our email accounts are not associated with a system user). You can use another UID and GID (other than 5000 as we do below) as long as it’s not in use and is a high number:

# groupadd -g 5000 vmail 
# useradd -g vmail -u 5000 vmail -d /home/vmail -m

The settings for Dovecot are split across several configuration files (make sure the following lines are uncommented and / or edit them to match the settings indicated below).

In /etc/dovecot/dovecot.conf:

dovecot.cf
!include_try /usr/share/dovecot/protocols.d/*.protocol
protocols = imap pop3 lmtp
!include conf.d/*.conf
!include_try local.conf

In /etc/dovecot/conf.d/10-auth.conf (only enable authentication through SQL and leave other authentication methods commented out):

10-auth.conf
disable_plaintext_auth = yes
auth_mechanisms = plain login
!include auth-sql.conf.ext

In /etc/dovecot/conf.d/auth-sql.conf.ext (note that we will store emails within a directory named yourdomain.com inside /home/vmail, which you need to create if it doesn’t exist. In our case we did mkdir /home/vmail/linuxnewz.com to manage emails for that domain):

auth-sql.conf.ext
passdb {
  driver = sql
  args = /etc/dovecot/dovecot-sql.conf.ext
}
userdb {
  driver = static
  args = uid=vmail gid=vmail home=/home/vmail/%d/%n/Maildir
}

Individual inboxes for user accounts will be created when emails for such accounts are first received.

In /etc/dovecot/conf.d/10-mail.conf:

10-mail.conf
mail_location = maildir:/home/vmail/%d/%n/Maildir
namespace inbox {
  inbox = yes
}
mail_privileged_group = mail
mbox_write_locks = fcntl

In /etc/dovecot/conf.d/10-master.conf:

10-master.conf
service imap-login {
  inet_listener imap {
    port = 143
  }
  inet_listener imaps {
  }
}
service pop3-login {
  inet_listener pop3 {
    port = 110
  }
  inet_listener pop3s {
  }
}
service lmtp {
  unix_listener /var/spool/postfix/private/dovecot-lmtp {
   mode = 0600
   user = postfix
   group = postfix
  }
}
service auth {
  unix_listener /var/spool/postfix/private/auth {
    mode = 0666
    user = postfix
    group = postfix
  }
  unix_listener auth-userdb {
   mode = 0600
   user = vmail
  }
  user = dovecot
}
service auth-worker {
  user = vmail
}
service dict {
  unix_listener dict {
  }
}

In /etc/dovecot/conf.d/10-ssl.conf (replace the certificate and key paths if you are planning on using a certificate signed by a CA):

10-ssl.conf
ssl = required
ssl_cert = </etc/pki/dovecot/certs/dovecot.pem
ssl_key = </etc/pki/dovecot/private/dovecot.pem

In /etc/dovecot/dovecot-sql.conf.ext enter your database information and the credentials of the administrative user created in Part 1.

Important: if your password contains an asterisk (#), you will need to enclose the connect string as indicated in the example below:

dovecot-sql.conf.ext
driver = mysql
connect = "host=127.0.0.1 dbname=EmailServer_db user=dba password=PassWith#Here"
default_pass_scheme = SHA512-CRYPT
password_query = SELECT Email as User, password FROM Users_tbl WHERE Email='%u';

Additionally, you can configure logging for Dovecot to be separate from Postfix in /etc/dovecot/conf.d/10-logging.conf:

log_path = /var/log/dovecot.log

Finally, make sure the Dovecot log is accessible for user dovecot:

# chown vmail:dovecot /var/log/dovecot.log
# chmod 660 /var/log/dovecot.log

Verify and Fix Postifix Configuration and Enable SMTP, POP3, and IMAP in Firewall

If you happen to run into any issues while configuring Postfix and / or Dovecot, instead of submitting all of the configuration files to ask for help, you can get a configuration summary (uncommented lines only) with:

# postconf –n # Summary for /etc/postfix/main.cf
# postconf –M # Summary for /etc/postfix/master.cf
# doveconf –n # Summary of all configuration files for Dovecot

In addition, make sure that the email inboxes are readable by vmail only:

# chown –R vmail:vmail /home/vmail

Configuration files should also be readable by vmail and dovecot users:

# chown -R vmail:dovecot /etc/dovecot 
# chmod -R o-rwx /etc/dovecot 

Finally, make sure you enable SMTP, POP3, and IMAP through the firewall:

# firewall-cmd --add-port=143/tcp
# firewall-cmd --add-port=143/tcp --permanent
# firewall-cmd --add-port=110/tcp
# firewall-cmd --add-port=110/tcp --permanent
# firewall-cmd --add-port=587/tcp
# firewall-cmd --add-port=587/tcp --permanent

Configure Thunderbird as an Email Client for Postfix

Having secured access through the firewall for the ports used in email communications, it’s time to configure an email client. Using [email protected] and its corresponding password, along with mail.linuxnewz.com as IMAP (or POP3) and SMTP server we are ready to start sending and receiving emails to and from such account:

Postfix: Configure Thunderbird Client
Postfix: Configure Thunderbird Client

You can safely disregard the warning message that is shown because you are using a certificate that is not signed by a trusted 3rd-party CA:

Thunderbird: Add Security Exception
Thunderbird: Add Security Exception

Let’s compose a brief test email and click Send:

Compose A Email on Thunderbird
Compose A Email on Thunderbird

When prompted to accept the self-signed certificate for the outgoing server, confirm it previously as before:

Thunderbird: Accept SSL Certificate
Thunderbird: Accept SSL Certificate

Finally, go to the destination email to see if you received the email that was just sent. If so, reply to it and see if it is delivered back to the source email inbox (otherwise, refer to the Postfix log at /var/log/maillog or the Dovecot log at /var/log/dovecot.log for troubleshooting information):

Verify Postfix and Dovecot Email Delivery
Verify Postfix and Dovecot Email Delivery

You now have a working Postfix and Dovecot email server and can start sending and receiving emails.

Summary

In this article we have explained how to configure Postfix and Dovecot to handle email traffic in your Linux server. If something does not work as indicated in this article, make sure you take time to check the Postfix and Dovecot documentation.

Please note that although setting up a Postfix mail server is not an easy task, it is a rewarding experience for every system administrator.

If after going through the docs you find yourself still struggling with Postfix and / or Dovecot, feel free to drop us a note using the comment form below and we will be glad to help you (don’t forget to upload to an online storage service the Postfix and Dovecot configuration as retrieved using postconf and doveconf as outlined in this article).

Gabriel Cánepa
Gabriel Cánepa is a GNU/Linux sysadmin and web developer from Villa Mercedes, San Luis, Argentina. He works for a worldwide leading consumer product company and takes great pleasure in using FOSS tools to increase productivity in all areas of his daily work.

Each tutorial at TecMint is created by a team of experienced Linux system administrators so that it meets our high-quality standards.

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100 thoughts on “How to Configure Postfix and Dovecot with Virtual Domain Users in Linux – Part 2”

  1. Hi,

    I just update my Centos 9, I follow the steps

    # chown vmail:dovecot /var/log/dovecot.log
    # chmod 660 /var/log/dovecot.log
    

    But in the /var/log/maillog, I got an error.

    Error: net_connect_unix(/run/dovecot/stats-writer) failed: Permission))
    

    I do see /var/log/dovecot.log with no issue.

    I still can send & receive emails though.

    What is the cause on this?

    Many thanks and great instructions!

    Reply
  2. Hi,

    Thank you for your great tutorial! There is one issue though.

    I can now send email using thunderbird to my Gmail account and Gmail actually receives it. However, I look at the raw header from Gmail. It shows

    Received: from T320.localdomain ([my-ip-address]).

    Where T320 is my Linux hostname. How can I make it show the actual domain, such as mydomain.com, as below:

    Received: from mydomain.com ([my-ip-address]).

    My machine has two domains pointing to it with same ip address….

    Reply
    • Not getting any answer?

      Here is the raw header from Gmail

      Received: by T320.localdomain (Postfix, from userid 1000) id 90B1920813085; Wed,

      I wish it is

      Received: by mydomain.com (Postfix, from userid 1000) id 90B1920813085; Wed,

      Reply
  3. Password mismatch? Check my comment in the first part of this article.

    I will quote it here:

    After hours and hours just found the issue…

    `password` VARCHAR(100) NOT NULL,

    But the result of

    ENCRYPT(‘PasswordForFirstEmailAccount’, CONCAT(‘$6$’, SUBSTRING(SHA(RAND()), -16)))

    will always exceed 100 characters

    Reply
  4. Hi there I keep getting password mismatch error when trying to login, and I am sure I’ve entered the correct password. Any idea why this happened ?

    auth-worker(403): Debug: sql([email protected],127.0.0.1): query: SELECT Email as user, password FROM Users_tbl WHERE Email='[email protected]';

    Jul 29 14:04:33 auth-worker(403): Info: sql([email protected],127.0.0.1): Password mismatch

    please help me it’s been 1 week and i have no idea how to fix this

    Reply
  5. I have successfully installed virtual domain postfix with dovecot. my server supports regexp, but i am unable to write rule for following

    abc.mydomain.com should send/receive email to/from abc.mydomain.com only
    xyz.mydomain.com should send/receive email to/from xyz.mydomain.com only
    abc.blahdomain.com should send/receive email to/from abc.blahdomain.com only
    

    it didn’t work with my regex, Please guide.

    Reply
  6. Hi,

    For me Ubuntu-18.04 dovecot lib path is /usr/lib/dovecot not /usr/libexec.

    Re
    dovecot unix – n n – – pipe
    flags=DRhu user=vmail:vmail argv=/usr/lib/dovecot/deliver -f ${sender} -d ${user}@${nexthop}

    Reply
  7. Hi, knowledgeable once. Can you please answer one of my question

    drwsrws--T  4  vmail                vmail 4096 Mar 14 17:15 .
    drwxr-xr-x 16   vmail                vmail 4096 Mar 14 13:15 ..
    drwxrws--T  4 fvmail                vmail 4096 Mar 14 17:11 fzela.com
    drwxrws--T  3   vmail               vmail 4096 Mar 14 17:15 fzmail.com
    

    I want mailbox structure like this where fzela.com and fzmail.com are domain which contain permission of root directory and inside domain for example fzela.com , I want user permission like this

    drwxrws--T 4    vmail                            vmail 4096 Mar 14 17:11 .
    drwsrws--T 4    vmail                            vmail 4096 Mar 14 17:15 ..
    drwx--S--- 3       fzinnus123.fzela         vmail 4096 Mar 14 17:10 fzinnus123
    drwx--S--- 3       fzinnus123.fzela         vmail 4096 Mar 14 17:11 fzsaran123
    

    where fzinnus123 and fzsaran123 are users for fzela.com domain.

    I tried a lots but unable to get in mycase my using virtual users

    Reply
  8. I love these kinds of articles, do any of them work?

    For all us newer users, this article would be fantastic if….Just post the complete config file for postfix/dovecot….Do the mods, file creation, databases, etc and done.

    Reply
  9. Hi,

    I have configured a local email server according to your article. I am having a problem when connecting through thunderbird. It keeps saying the password is incorrect. But the password is correct. The dovecot.log gives the authentication failed error. Could you please help me on this?

    Reply
  10. Hello Gabriel Cánepa, well done on the tutorial, I managed to follow it through and though I had to tweak a bit to get things going I finally did it and it’s working fine, I can receive messages!

    But I am afraid I cannot send such, sending to other addresses which doesn’t belong to the local host such @gmail.com, @yahoo.com, etc. fails, as if the server is trying to connect them using SMTP.

    Here are few errors which might help you straight what I mean out:

    Sep 28 12:51:40 us00 postfix/smtp[2491]: connect to mx10.mailspamprotection.com[184.154.177.50]:25: Connection timed out
    Sep 28 12:51:40 us00 postfix/smtp[2491]: A25613F0E5: to=, relay=none, delay=227, delays=72/0.03/155/0, dsn=4.4.1, status=deferred (connect to mx10.mailspamprotection.com[184.154.177.50]:25: Connection timed out)

    Sep 28 12:51:35 us00 postfix/smtp[2490]: A42F93F0AC: to=, relay=none, delay=2358, delays=2208/0.02/150/0, dsn=4.4.1, status=deferred (connect to alt4.gmail-smtp-in.l.google.com[74.125.193.27]:25: Connection timed out)
    Sep 28 12:51:35 us00 postfix/smtp[2493]: 1692A3F0D8: to=, relay=none, delay=2278, delays=2128/0.04/150/0, dsn=4.4.1, status=deferred (connect to alt4.gmail-smtp-in.l.google.com[74.125.193.27]:25: Connection timed out)

    Please bare in mind that these two are email addresses hosted externally.

    I have followed all settings in the tutorial, my MX record is pointing to:mx.domain.tld, PTR to mx.domain.tld and mx.domain.tld A Record.

    I am honestly not sure what shall I tweak or do to make sure emails are going back and forth.

    Hopefully you can help!

    Reply
  11. Centos 7.5, pointing dovecot log file to /var/log/dovecot.log with suggested permissions results with the following error.

    Jul 02 21:03:48 domain.com dovecot[5708]: Can’t open log file /var/log/dovecot.log: Permission denied

    Event chmod 777 /var/log/dovecot.log didn’t help

    Reply
  12. The problem with de line argv=/usr/libexec/dovecot/deliver is the indentation. I have the error message “bad field count” until i put 2 spaces before the argv=.

    Reply
  13. help me! when i go to step

    Before you save changes, add the following lines at the bottom of the file:
    master.cf

    [root@sv conf.d]# postfix check
    /usr/sbin/postconf: fatal: file /etc/postfix/master.cf: line 129: bad field count

    Reply
    • @Le,

      Go the line 129 in master.cf file and check for any extra spaces or use correct spacing..

      dovecot   unix  -       n       n       -       -       pipe
          flags=DRhu user=vmail:vmail argv=/usr/libexec/dovecot/deliver -f ${sender} -d ${recipient}
      
      Reply
      • There needs to be space before “flags” (or after pipe). If you are copying and pasting, you need to add it manually.

        dovecot unix – n n – – pipe
        flags=DRhu user=vmail:vmail argv=/usr/libexec/dovecot/deliver -f ${sender} -d ${recipient}

        Reply
  14. Hello Gabriel A. Cánepa,

    Me too have the same issue, Please comment on this. I have doubt the path “argv=/usr/libexec/dovecot/deliver” in line 134. Is it matching with your tutorial ? Actually that line needs a bit explanation, please consider. thanking you in advance….

    /usr/sbin/postconf: fatal: file /etc/postfix/master.cf: line 134: bad field count
    postfix/postlog: warning: inet_protocols: disabling IPv6 name/address support: Address family not supported by protocol
    postfix/postfix-script: fatal: cannot execute /usr/sbin/postconf!

    Reply
  15. Good evening Gabriel Cánepa,

    Thank you very much for your presentation.
    What should I change if I want the Samba4 LDAP instead of MariaDB? Thank you.

    Reply
  16. I can’t login into the mail server

    May 19 17:29:28 imap-login: Info: Aborted login (auth failed, 5 attempts in 10 secs): user=, method=PLAIN, rip=140.0.249.109, lip=10.10.10.16, TLS: Disconnected, session=

    Reply
  17. I have a small issue and I can’t seem to find a reason for it. about 5 times a day, I get email addressed to other users on my server. I have enabled verbose logging on postfix and dovecot but I can find no correlation between the logs and the email being sent to the wrong inbox. I am perplexed. Any ideas?

    Reply
    • Hi Eric,
      This is very strange. If you can post the logs somewhere and indicate what are the right and wrong email addresses, I would be glad to take a look.

      On a side note, when an email is sent to the wrong inbox, does the “right” recipient also get a copy or not? Additionally, how did you become aware of this issue and how were you able to determine where the email had gone?

      Reply
      • I’ll have to work on getting the logs. I will have to search logs by message ID and figure out which ones are being delivered incorrectly.

        The reason I know this is happening is I get other users email, email not addressed to me, but others in the database.

        I’ll work on the logs and get back to you.

        Reply
      • I believe whats happening is my email gateway, ScrolloutF1, is marking these messages and sending them to a collector email that aliases to my email. I traced one email in particular and it is forwarded to the collector email address and then it gets delivered to me.

        That may be the issue.I’ll keep you posted.

        Thank you for the prompt reply.

        Reply
  18. Hi, great article,

    After setting everything up I successfully telnet to the server over port 993 (143 does not pass the SSL routine), but I am unable to login.

    any ideas?

    Reply
  19. I’m using ScrolloutF1 for email security and it seems to work great, but I want to send spam reports to the Admin user for each domain. In other words, I would like to forward my spam filter collector address to a distribution group.

    Can you explain how to “Alias” a distribution group so an email can be sent to many recipients at once?

    Besides creating the group, I would need to add members.

    Any help would be greatly appreciated.

    Reply
  20. Tomthevth,

    You need a leading space in front of the line and the error will be resolved. With no space, it does give a config error.
    I hope this helps.

    Reply
  21. I’m getting postfix error when editing the /etc/postfix/master.cf
    /usr/sbin/postconf: fatal: file /etc/postfix/master.cf: line 131:

    Line 131 is the added flag line:
    flags=DRhu user=vmail:vmail argv=/usr/libexec/dovecot/deliver -f ${sender} -d ${recipient}

    Someone any idea?

    Thanks

    Reply
    • I had a same issue because of white spaces copy any similar line
      from the file (master.cf) and change it as given instruction should work

      Reply
  22. S Shah, If you created the user table with password VARCHAR(100) thats the issue. Recreate it with VARCHAR(250) and it will work. The SHA512 encryption makes the password longer than the 100 characters defined.
    Hope this helps.

    Reply
  23. Now I’m back to this:
    mail postfix/qmgr[11148]: warning: connect to transport private/dovecot: Connection refused

    I am going to uninstall and reinstall postfix and dovecot unless I hear back from you soon. I have to get this going.

    Reply
  24. Jan 13 04:48:00 mail postfix/master[3845]: warning: process /usr/libexec/postfix/pipe pid 5338 exit status 1
    Jan 13 04:48:00 mail postfix/qmgr[3861]: warning: private/dovecot socket: malformed response
    Jan 13 04:48:00 mail postfix/qmgr[3861]: warning: transport dovecot failure — see a previous warning/fatal/panic logfile record for the problem description

    postconf -n:

    append_dot_mydomain = no
    biff = no
    command_directory = /usr/sbin
    config_directory = /etc/postfix
    daemon_directory = /usr/libexec/postfix
    data_directory = /var/lib/postfix
    debug_peer_level = 2
    debugger_command = PATH=/bin:/usr/bin:/usr/local/bin:/usr/X11R6/bin ddd $daemon_directory/$process_name $process_id & sleep 5
    html_directory = no
    inet_interfaces = all
    inet_protocols = all
    mail_owner = postfix
    mailq_path = /usr/bin/mailq.postfix
    manpage_directory = /usr/share/man
    message_size_limit = 4194304
    queue_directory = /var/spool/postfix
    readme_directory = no
    sample_directory = /usr/share/doc/postfix-2.10.1/samples
    sendmail_path = /usr/sbin/sendmail.postfix
    setgid_group = postdrop
    smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
    smtpd_banner = $myhostname ESMTP $mail_name (CentOS)
    smtpd_sasl_path = private/auth
    smtpd_sasl_type = dovecot
    smtpd_tls_cert_file = /etc/pki/dovecot/certs/dovecot.pem
    smtpd_tls_key_file = /etc/pki/dovecot/private/dovecot.pem
    smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
    smtpd_use_tls = yes
    unknown_local_recipient_reject_code = 550
    virtual_alias_maps = mysql:/etc/postfix/mariadb-valias.cf
    virtual_mailbox_domains = mysql:/etc/postfix/mariadb-vdomains.cf
    virtual_mailbox_maps = mysql:/etc/postfix/mariadb-vusers.cf
    virtual_transport = dovecot

    postconf -n:

    # 2.2.10: /etc/dovecot/dovecot.conf
    # OS: Linux 3.10.0-514.2.2.el7.x86_64 x86_64 CentOS Linux release 7.3.1611 (Core) xfs
    auth_mechanisms = plain login
    first_valid_uid = 1000
    log_path = /var/log/dovecot.log
    mail_location = maildir:/home/vmail/%d/%n/Maildir
    mail_privileged_group = mail
    mbox_write_locks = fcntl
    namespace inbox {
    inbox = yes
    location =
    mailbox Drafts {
    special_use = \Drafts
    }
    mailbox Junk {
    special_use = \Junk
    }
    mailbox Sent {
    special_use = \Sent
    }
    mailbox “Sent Messages” {
    special_use = \Sent
    }
    mailbox Trash {
    special_use = \Trash
    }
    prefix =
    }
    passdb {
    args = /etc/dovecot/dovecot-sql.conf.ext
    driver = sql
    }
    service auth-worker {
    user = vmail
    }
    service auth {
    unix_listener /var/spool/postfix/private/auth {
    group = postfix
    mode = 0666
    user = postfix
    }
    unix_listener auth-userdb {
    mode = 0600
    user = vmail
    }
    user = dovecot
    }
    service imap-login {
    inet_listener imap {
    port = 143
    }
    }
    service lmtp {
    unix_listener /var/spool/postfix/private/dovecot-lmtp {
    group = postfix
    mode = 0600
    user = postfix
    }
    }
    service pop3-login {
    inet_listener pop3 {
    port = 110
    }
    }
    ssl = required
    ssl_cert = </etc/pki/dovecot/certs/dovecot.pem
    ssl_key = </etc/pki/dovecot/private/dovecot.pem
    userdb {
    args = uid=vmail gid=vmail home=/home/vmail/%d/%n/Maildir
    driver = static
    }

    I don't think authentication is the issue at all. I believe that the pid file is corrupt or the process is. I am connected with an email client, can send email anywhere, and email hits the server. Once it's on the server, delivery fails I think due to the process failing and exiting in the error I mentioned earlier.

    I failed to thank you for the article. Its a great article and will make managing multiple domains and users easier.

    One question: What do you recommend for this setup for webmail? I would like to incorporate that into the setup for user convenience.

    Thank you again for the article.

    Reply
  25. Hello Gabriel,

    thank you for this great Guide.

    Sending a mail works like it should, but receiving not.

    If I try to send a Mail via telnet it looks like this:

    openssl s_client -debug -starttls smtp -crlf -connect myhost:587
    ...
    250 DSN
    HELO sender.com
    ...
    250 server.com
    MAIL FROM:
    ...
    250 2.1.0 Ok
    RCPT TO:
    

    at this point i don’t receive a ack code like (250 2.1.5 Ok) this should be an sign for an error, but the log does not say anything

    DATA
    ...
    554 5.5.1 Error: no valid recipients
    Subject: Testmsg
    ...
    221 2.7.0 Error: I can break rules, too. Goodbye.
    ---> Exit
    

    (The “…” shows parts of the ssl communication)

    In the postfix logfile is nothing.

    Reply
    • Ok i find out, that on the next Page (“How to Add Antivirus and Spam Protection”) in the configuration file /etc/postfix/master.cf the smtp service is configured as inet type. In this section it should be configured as unix type. So which should i use?

      Set to “inet” -> restart -> maillog after sending an email:
      warning: do not list domain xxx.xx in BOTH mydestination and virtual_mailbox_domains
      NOQUEUE: reject: RCPT from mail-vk0-f47.google.com[209.85.213.47]: 550 5.1.1 : Recipient address rejected: User unknown in local recipient table; from= to= proto=ESMTP helo=

      Reply
  26. When sending a test email to postfix/error[19255]: 020D02159E3: to=, relay=none, delay=0.1, delays=0.04/0.02/0/0.04, dsn=4.3.0, status=deferred (mail transport unavailable)
    myself I get: postfix/qmgr[19096]: warning: connect to transport private/dovecot: Connection refused

    I can send outside, but not to myself.

    This is a local email account only, no public MX record but I have mx record on my dns server and use it to get logs for devices emailed to me.
    Please help.

    Reply
  27. I got everything worked out except; I can send email any where in the world, but it’s not relaying inside the mail server. In other words, if I have a user called [email protected], it will send the email but it states the there is no relay for that user. It finds it in the database and authenticates, etc, but when queued, it never gets delivered. I’ve been over this 100 times and not sure why its not relaying local.
    Any suggestions?

    I can post error message if you need me to.
    Thanks.

    Reply
  28. I figured out that the query returns an empty result, hence, user not authenticated. I can run the query on the db and specify an ID, but with the query in vusers.cf and vdomains.cf, it is not returning a value. How do I correct this?

    Reply
    • Eric – can you send me (or post online) your configuration files and database diagram? I’ll compare with the ones used in our setup and get back to you. Please obfuscate any personal information.

      Reply
  29. I have resolved the flags error. I needed to put a space in front of the line and the problem went away.

    However, after much trouble shooting I am stumped as to why my login is being rejected. I removed and recreated the account in mariadb making sure my password is correct, queried the db to ensure my account exists and my domain exists. I went through every file line by line, but it’s rejecting my login. I am at a loss.

    Please help.
    Thanks.

    Reply
  30. When I add the line at the end of master.cf.

    flags=DRhu user=vmail:vmail argv=/usr/libexec/dovecot/deliver -f ${sender} -d ${recipient}
    

    I get

    fatal: file /etc/postfix/master.cf: line 130: bad field count
    

    Commenting the line removes the error.
    Suggestions?

    Reply
  31. Hello @Gabriel,

    First of all, thank you for the great article.

    I have some issues though: after following this tutorial, and checking all steps few times, I have problems with receiving e-mails. I’m able to send e-mail to everyone, but e-mails from outside domains (e.g. gmail) are not excepted by my mail server. We are using public IP address for mail server. And also, gmail gives me notification that my mail server did not encrypt the message. I’m using let’s encrypt as CA, and their cert and key (fullchain.pem and privkey.pem respectively).

    From postfix.com:

    “By default, TLS is disabled in the Postfix SMTP server, so no difference to plain Postfix is visible. Explicitly switch it on with “smtpd_tls_security_level = may”. ”

    smtpd_use_tls = yes is termed legacy. Could this be the cause of the problem?

    “By default, TLS is disabled in the Postfix SMTP server, so no difference to plain Postfix is visible. Explicitly switch it on with “smtpd_tls_security_level = may”.”

    Reply
    • Ivan – can you send me (or post online) your configuration files and database diagram? I’ll compare with the ones used in our setup and get back to you.

      Reply
  32. So my problem is .. i am on the of the part 2 so i am trying setup Thunderbird but i have a problem. I can connect to my mail server and get the folders (inbox, draft, trash) and i think download mails via imap (this i can’t test because i don’t have any emails).

    But smtp still not work..Thunderbird shows me error that connection to my mail server failed and nothing shows in logs.. Telnet works i cant normally send email… Another thing when i send email from gmail to my server then gmail send me back error message.

    this is my log when i connect to sync my emails.. there are some unknown user auth-worker messages and some pam auth messages

    Oct 05 07:44:01 auth: Debug: Loading modules from directory: /usr/lib64/dovecot/auth
    Oct 05 07:44:01 auth: Debug: Module loaded: /usr/lib64/dovecot/auth/libdriver_mysql.so
    Oct 05 07:44:01 auth: Debug: Module loaded: /usr/lib64/dovecot/auth/libdriver_sqlite.so
    Oct 05 07:44:01 auth: Debug: Read auth token secret from /var/run/dovecot/auth-token-secret.dat
    Oct 05 07:44:01 auth: Debug: auth client connected (pid=7486)
    Oct 05 07:44:01 auth: Debug: auth client connected (pid=7489)
    Oct 05 07:44:01 auth: Debug: client in: AUTH    1       PLAIN   service=imap    secured session=2TQQqhc+bgBY1CMG 
    lip=myip       rip=88.212.35.6 lport=143       rport=54382
    Oct 05 07:44:01 auth: Debug: client passdb out: CONT    1
    Oct 05 07:44:01 auth: Debug: client in: CONT
    Oct 05 07:44:01 auth-worker(7491): Debug: Loading modules from directory: /usr/lib64/dovecot/auth
    Oct 05 07:44:01 auth-worker(7491): Debug: Module loaded: /usr/lib64/dovecot/auth/libdriver_mysql.so
    Oct 05 07:44:01 auth-worker(7491): Debug: Module loaded: /usr/lib64/dovecot/auth/libdriver_sqlite.so
    Oct 05 07:44:01 auth-worker(7491): Debug: pam(richardrozbrj@xxx,88.212.35.6): lookup service=dovecot
    Oct 05 07:44:01 auth-worker(7491): Debug: pam(richardrozbrj@xxx,88.212.35.6): #1/1 style=1 msg=Password:
    Oct 05 07:44:03 auth-worker(7491): Info: pam(richardrozbrj@xxx,88.212.35.6): pam_authenticate() 
    failed: Authentication failure (password mismatch?)
    Oct 05 07:44:03 auth-worker(7491): Debug: sql(richardrozbrj@xxx,88.212.35.6): query: 
    SELECT Email as User, password FROM Users_tbl WHERE Email='richardrozbrj@xxx';
    Oct 05 07:44:04 auth: Debug: client passdb out: OK      1       user=richardrozbrj@xxx      
     User=richardrozbrj@xxx
    Oct 05 07:44:04 auth: Debug: master in: REQUEST 1762394113      7489    1      
     1f4774e9be834b6150011787a313c10d        session_pid=7494        request_auth_token
    Oct 05 07:44:04 auth-worker(7491): Debug: passwd(richardrozbrj@xxx,88.212.35.6): lookup
    Oct 05 07:44:04 auth-worker(7491): Info: passwd(richardrozbrj@xxx,88.212.35.6): unknown user
    Oct 05 07:44:04 auth: Debug: master userdb out: USER    1762394113      richardrozbrj@xxx    
    uid=5000        gid=5000        home=/home/vmail/xxx/richardrozbrj/Maildir   
    auth_token=cd757c58520fbf318d9bccd8908aa798c536184c
    Oct 05 07:44:04 imap-login: Info: Login: user=, method=PLAIN, rip=88.212.35.6, lip=myip, mpid=7494, TLS, session=
    Oct 05 07:44:04 imap(richardrozbrj@xxx): Debug: Effective uid=5000, gid=5000, home=/home/vmail/xxx/richardrozbrj/Maildir
    Oct 05 07:44:04 imap([email protected]): Debug: Namespace inbox: type=private, prefix=, sep=, inbox=yes, hidden=no,
    list=yes, subscriptions=yes location=maildir:/home/vmail/xxx/richardrozbrj/Maildir
    Oct 05 07:44:04 imap([email protected]): Debug: maildir++: root=/home/vmail/xx/richardrozbrj/Maildir, 
    index=, indexpvt=, control=, inbox=/home/vmail/xxx/richardrozbrj/Maildir, alt=
    
    Reply
      • I am on the end of this part of tutorial… but my smtp connection via mail client doesn’t work… i can normally send email via telnet but not via client … it shows me error with smtp failed connection and no logs anywhere.

        Imap works i think because i connect and got folders so i think it can sync mail via server and client. Another thing is that when i want send email from gmail to my server it return error message to gmail that wasn’t successful.

        Is there any options how can i turn on logs for smtp ? because i trying connect but there is nothing in logs no messages for smtp.

        Reply
  33. I’ve installed all as is decribed in part 1 and 2, but the postfix don’t communicate with me.
    If I try to connect at port 25 with telnet, there isn’t answer.
    Could You describe how we can test the installation and how to set postfix to log in maillog file?

    Thanks for articles/help.
    Mareg

    Reply
  34. Hello, notice the last line in the master.cfg
    ” flags=DRhu user=vmail:vmail argv=/usr/libexec/dovecot/deliver -f ${sender} -d ${recipient}”
    must start with [space]

    Mareg

    Reply
      • I tried this again but its true. So if You look at examples in file, every second line with “flags” parameter had two spaces in the start of.

        Reply
  35. I’ve done everything step by step, but I can not send or receive any email, I opened port 25 and nothing … please some help … thank you

    Reply
  36. Ok I have an issue with /var/log/dovecot.log, apparently it was not created during the postfix configuration.. What can I do? can I just create that file under /var/log/?

    Reply
    • @Johnny,
      The log file should have been created if you followed the steps outlined in this series. What distribution are you using? If you’re using a distro other than CentOS, the file may be located somewhere else. Before creating it manually, I would do a search: find / -name “dovecot.log”.

      Reply
  37. I’ve been using this guide as a step-by-step literal how-to. At the point with header “Configuring Dovecot” I attempted to send mail to my server using a telnet session, both from localhost and from external. Connection was refused in all cases despite firewall being open on 25. The solution was to modify master.cf to add the line:

    smtp inet n – n – 1 smtpd

    I’ve got other issues at this point, but at least the server is accepting connection and responding to ehlo now. On CentOS7.2 x64.

    Reply
      • What? RTFM before posting? Why would I do that?

        BTW, the “other issues” I’ve got … spelling alias in my mariadb lookup cf as “alais”.

        I’m a doof. I’m going to keep plugging away at it anyways. Maybe I’ll have a functional server by the time I get to the end of this series.

        Reply
        • I advised you to check Part 3 of this series to point out that this had been properly addressed there. This setup was tested so I don’t see why you wouldn’t have a functional server once you complete this series.

          Reply
          • Oh, I don’t doubt the series. With stupid problems like spelling mistakes and freaking out about broken stuff before bothering to reading the entire process I’m questioning my ability to execute properly. But I’m learning plenty along the way, so I’m going to keep at it. I’ve tried a dozen different tutorials and I keep coming back to this one. It seems to make more sense and be laid out a bit more logically and informatively than most. If I can’t make it work, its on me.

        • @Harmon20,
          If for some reason you can’t make it work, don’t hesitate to let us know. I’m willing to share all the configuration files so you can compare them to your setup. We really want you to have the awesome feeling of having set up this complete mail server and make it work :).

          Reply
  38. I was having the same issue receiving emails from outside, i solved it with
    firewall-cmd –add-port=25/tcp
    firewall-cmd –add-port=25/tcp –permanent

    Reply
    • @JOSE,
      Good catch. Yes, you need to allow the appropriate traffic through the built-in firewall service.

      Reply
  39. Hi, i’ve follow the how to , and it works perfectly but just one important thing doesn’t work! I don’t receive the mail but i can send, why ?? I’ve rechecked the configuration file and it’s seem all ok!

    Reply
    • @Mario,
      First, check the logs. Can you see anything useful there?
      Next, check the my_networks directive in the Postfix configuration file. What does it say?

      Reply
      • I using a ec2 instance on amazon web service. Port 143 and 587 are reachable from outside.

        mynetworks = 172.31.16.0/24 127.0.0.0/8

        Into log message:

        dovecote.log:

        After I try to download mail from thunderbird

        Feb 25 17:33:48 auth: Info: mysql: Connected to 127.0.0.1 (EmailServer_db)
        Feb 25 17:34:02 imap-login: Info: Disconnected (auth failed, 3 attempts): user=, method=PLAIN, rip=82.48.31.30, lip=172.31.16.209, TLS
        Feb 25 17:34:07 imap-login: Info: Login: user=, method=PLAIN, rip=82.48.31.30, lip=172.31.16.209, mpid=31542, TLS
        Feb 25 17:34:07 imap(XXXXX): Info: Disconnected: Logged out bytes=8/328
        Feb 25 17:34:13 imap-login: Info: Login: user=, method=PLAIN, rip=82.48.31.30, lip=172.31.16.209, mpid=31544, TLS

        I substute in this paste [email protected] for privacy reason.

        Into maillog I don’t see anything when I try to download the mail from thunderbird. I see only log messages relative sent mail.

        Reply
        • @Mario,
          I would look into the Dovecot side of things. We don’t have this server anymore, but I kept a backup of the configuration files. Do you want me to send them to you? Other than that, I would go through the comments in these articles. What other users did may be helpful for you as well.

          Reply
          • # 2.0.9: /etc/dovecot/dovecot.conf
            # OS: Linux 4.1.17-22.30.amzn1.x86_64 x86_64 ext4
            auth_mechanisms = plain login
            listen = *
            log_path = /var/log/dovecot.log
            mail_location = maildir:/home/vmail/%d/%n/Maildir
            mail_privileged_group = mail
            mbox_write_locks = fcntl
            namespace inbox {
            inbox = yes
            location =
            prefix =
            }
            passdb {
            args = /etc/dovecot/dovecot-sql.conf.ext
            driver = sql
            }
            service auth-worker {
            user = vmail
            }
            service auth {
            unix_listener /var/spool/postfix/private/auth {
            group = postfix
            mode = 0666
            user = postfix
            }
            unix_listener auth-userdb {
            mode = 0600
            user = vmail
            }
            user = dovecot
            }
            service imap-login {
            inet_listener imap {
            port = 143
            }
            }
            service lmtp {
            unix_listener /var/spool/postfix/private/dovecot-lmtp {
            group = postfix
            mode = 0600
            user = postfix
            }
            }
            service pop3-login {
            inet_listener pop3 {
            port = 110
            }
            }
            ssl = required
            ssl_cert = </etc/pki/dovecot/certs/dovecot.pem
            ssl_key = </etc/pki/dovecot/private/dovecot.pem
            userdb {
            args = uid=vmail gid=vmail home=/home/vmail/%d/%n/Maildir
            driver = static
            }

            This is my dovecot configuration file obtained by doveconf -n. I has read the comment but i don't find a solution for my problem. I follow the suggestion of an user in the previously article (change VARCHAR(100) in VARCHAR(106) ) so, I think the problem wansn't authentication. Thanks for your support :)

          • @Mario,

            He will surely help you out, may be he kinda busy, just have patience, you will soon hear from him with solution..

        • @Mario,
          Another reader has commented that he had the same issue and he solved it by opening the right port in the firewall:
          firewall-cmd –add-port=25/tcp
          firewall-cmd –add-port=25/tcp –permanent
          Can you please give it a try and let us know if it worked?

          Reply
          • Yes, 25 port is open (i open it into amazon web service interface) but if I launch a nmap on localhost I get this:

            PORT STATE SERVICE
            21/tcp open ftp
            22/tcp open ssh
            80/tcp open http
            110/tcp open pop3
            111/tcp open rpcbind
            143/tcp open imap
            443/tcp open https
            587/tcp open submission
            993/tcp open imaps
            995/tcp open pop3s
            3306/tcp open mysql

            And, this is the nmap from remote:

            21/tcp open ftp
            22/tcp open ssh
            25/tcp closed smtp
            80/tcp open http
            110/tcp open pop3
            143/tcp open imap
            587/tcp open submission
            993/tcp open imaps
            995/tcp open pop3s

    • @Sam,

      Please tell us clearly and explain why this article is waste of time? where you’re facing problems, we’re here to help you out, but just don’t post meaning less comment here..

      Reply
  40. Two brilliant articles for configuring an email server on my new CentOS 7.2 system — thanks very much!

    But a typo in Part 1 of the article didn’t manifest itself until I hit the end of Part 2 — I kept getting authorization failed errors when trying to log in with my email client:

    imap-login: Info: Disconnected (auth failed, 1 attempts in 4 secs)

    After investigating further with some debug options turned on, it turned out to be a “Password mismatch” error — which I found was due the “password” field in the Users_tbl being defined as a 100 character field. But the encrypted password requires a minimum of 106 characters, so it was being truncated when stored in the database. Consequently, the password entered in the email client would never match the password in the database, and I would never be able to log in.

    When creating the Users_tbl in Step 13 in the Part 1 article, change the:

    `password` VARCHAR(100)

    reference to:

    `password` VARCHAR(106)

    or some other value larger than 106 and everything works great.

    For those who have already got this far, but cannot log in, run these SQL statements in your EmailServer_db to correct this issue:

    alter table Users_tbl modify column password varchar(106);

    and then update your email pasword in the database for each email account:

    update Users_tbl set password=ENCRYPT(‘MyPasswordHere’, CONCAT(‘$6$’, SUBSTRING(SHA(RAND()), -16))) where Email=’MyEmailAccountHere’;

    Once I did that, everything worked perfectly.

    Reply
  41. Hi
    I have the same issue as @Georg has. I set up everything according this guide, but I am not able to configure an email account in Thunderbird. It keeps saying that no settings for my mail account could be found.
    Do you have any idea what could be wrong?
    Regards, Phrosgone

    Reply
  42. Hi Gabriel,

    I was following the instructions letter by letter and had no mistakes.
    At the ‘Configure Thunderbird as an Email Client for Postfix’ step I stumbled upon an error that looks strange to me:

    Server is accessible, I see a Dovecot prompt at port 143, but neither Thunderbird nor Apple Mail won’t recognize a valid IMAP login attempt.

    What I see in the logs is:

    Nov 27 12:12:23 urbi postfix/submission/smtpd[3237]: connect from ip.hostname.net[46.xxx.xxx.xxx]
    Nov 27 12:12:26 urbi postfix/submission/smtpd[3237]: warning: ip.hostname.net[46.xxx.xxx.xxx]: SASL PLAIN authentication failed:
    Nov 27 12:12:26 urbi postfix/submission/smtpd[3237]: disconnect from ip.hostname.net[46.xxx.xxx.xxx]
    Nov 27 12:12:36 urbi postfix/submission/smtpd[3237]: lost connection after AUTH from ip.hostname.net[46.xxx.xxx.xxx]
    Nov 27 12:12:36 urbi postfix/submission/smtpd[3237]: disconnect from de2x.mullvad.net[46.165.208.203]
    Nov 27 12:14:16 urbi dovecot: auth: Warning: auth client 0 disconnected with 1 pending requests: EOF
    Nov 27 12:15:51 urbi dovecot: imap-login: Disconnected (no auth attempts in 15 secs): user=, rip=46.xxx.xxx.xxx, lip=xx.xx.xx.xx, TLS handshaking: Disconnected, session=
    Nov 27 12:15:54 urbi dovecot: imap-login: Aborted login (auth failed, 1 attempts in 2 secs): user=, method=PLAIN, rip=xx.xx.xx.xx, lip=xx.xx.xx.xx, TLS, session=

    Thunderbird is able to autodetect ports (143/587) and STARTTLS as a Security setting, keeps telling me “Maybe the password is wrong?”
    I deleted the user and created it again with a password that has no special characters – only letters/numbers – it did not help.

    Any ideas what could be wrong?

    Thanks,
    Georg

    Reply
  43. To whom it may concern if you have trouble sending mails or if postfix has trouble connecting to db (keep in mind i used mysql instead of mariadb).

    A quick installation of postfix-mysql may solve your issue “sudo apt-get install postfix-mysql”

    Reply
  44. I have actually successfully set up a server a couple of times successfully using this guide using ubuntu 14. There were just a few tweaks I had to make. Can’t remember them with out actually going through the process, so i’ll just post as I remember.

    Another required tweak I had to make for receiving mail…

    One reason that you are not recieving mail may be that dovecot is not actually listening on the imap(143) or pop3(110) ports.
    You can check this with the command “netstat -nl4”

    If this is the case look in dovecot.conf and uncomment the line “listen = *,::”
    If your server does not support ipv6 you can also remove the “,::”

    Reply
  45. For anyone who has trouble recieving mail, if your are using ubuntu the information in master.cf may be wrong. The guide says to add a line at the end of master.cf in /etc/postfix

    In the snippet the guide has you add at the bottom it has argv=/usr/libexec/dovecot/deliver
    Make sure that folder exists if not, it is most likely argv=/usr/lib/dovecot/deliver as it was with mine.

    Reply
  46. @Rocky,
    Please refer to the last paragraph in the Summary section of this article: “…feel free to drop us a note using the comment form below and we will be glad to help you (don’t forget to upload to an online storage service the Postfix and Dovecot configuration as retrieved using postconf and doveconf as outlined in this article).”
    Unfortunately, the information provided by the logs is not enough to troubleshoot this issue – that is why I asked readers to submit their configuration files in order for me to take a look. Feel free to obfuscate your IP address and passwords with letters or signs.
    What I can tell you for sure is that Postfix / Dovecot are not seeing your virtual users accounts. So that makes me think they’re not having access to the database. But I’m afraid that’s all I can tell without looking at your config files. Look forward to hearing from you!

    Reply
    • Hi Gabriel,

      Thanks for your reply…

      I had successfully configured mail server for single domain before, so it’s all DNS,PTR and MX records are correctly set.
      EMAILS sending and receiving are working fine on that VM.

      But here for virtual domain mail server’s VM ( issue ) :
      – I am able to send emails but not receiving it from external servers.. for example GMAIL,HOTMAIL, etc

      Here are my main.cf,master.cf and dovecot configuration ( as it was not working with given setting…I slightly modified it..)

      ——————————————–
      MAIN.CF
      ————————————————————————————————————————————
      alias_database = hash:/etc/aliases
      alias_maps = hash:/etc/aliases
      append_dot_mydomain = no
      biff = no
      command_directory = /usr/sbin
      config_directory = /etc/postfix
      daemon_directory = /usr/libexec/postfix
      data_directory = /var/lib/postfix
      debug_peer_level = 2
      debugger_command = PATH=/bin:/usr/bin:/usr/local/bin:/usr/X11R6/bin ddd $daemon_directory/$process_name $process_id & sleep 5
      dovecot_destination_recipient_limit = 1
      home_mailbox = Maildir/
      html_directory = no
      inet_interfaces = all
      inet_protocols = ipv4
      mail_owner = postfix
      mailq_path = /usr/bin/mailq.postfix
      manpage_directory = /usr/share/man
      message_size_limit = 4194304
      milter_default_action = accept
      milter_protocol = 2
      mydestination = localhost, localhost.localdomain
      mydomain = example.com
      myhostname = mail.example.com
      mynetworks = 127.0.0.0/8, 192.168.56.0/24, 27.5.68.0/24
      myorigin = example.com
      newaliases_path = /usr/bin/newaliases.postfix
      non_smtpd_milters = $smtpd_milters
      queue_directory = /var/spool/postfix
      readme_directory = no
      sample_directory = /usr/share/doc/postfix-2.10.1/samples
      sendmail_path = /usr/sbin/sendmail.postfix
      setgid_group = postdrop
      smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
      smtpd_banner = $myhostname NO UCE ESMTP
      smtpd_milters = inet:127.0.0.1:8891
      smtpd_sasl_path = private/auth
      smtpd_sasl_type = dovecot
      smtpd_tls_cert_file = /etc/pki/dovecot/certs/dovecot.pem
      smtpd_tls_key_file = /etc/pki/dovecot/private/dovecot.pem
      smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
      smtpd_use_tls = yes
      unknown_local_recipient_reject_code = 550
      virtual_alias_domains =
      virtual_alias_maps = mysql:/etc/postfix/mariadb-valias.cf
      virtual_gid_maps = static:5000
      virtual_mailbox_base = /home/vmail
      virtual_mailbox_domains = mysql:/etc/postfix/mariadb-vdomains.cf
      virtual_mailbox_maps = mysql:/etc/postfix/mariadb-vusers.cf
      virtual_transport = dovecot
      virtual_uid_maps = static:5000

      ——————————————–
      MASTER.CF
      ————————————————————————————————————————————
      smtp inet n – n – – smtpd
      submission inet n – n – – smtpd
      -o syslog_name=postfix/submission
      -o smtpd_tls_security_level=encrypt
      -o smtpd_sasl_auth_enable=yes
      -o smtpd_reject_unlisted_recipient=no
      -o smtpd_recipient_restrictions=permit_sasl_authenticated,reject
      -o milter_macro_daemon_name=ORIGINATING
      smtps inet n – n – – smtpd
      -o syslog_name=postfix/smtps
      -o smtpd_tls_wrappermode=yes
      -o smtpd_sasl_auth_enable=yes
      -o smtpd_recipient_restrictions=permit_sasl_authenticated,reject
      -o milter_macro_daemon_name=ORIGINATING
      pickup unix n – n 60 1 pickup
      cleanup unix n – n – 0 cleanup
      qmgr unix n – n 300 1 qmgr
      tlsmgr unix – – n 1000? 1 tlsmgr
      rewrite unix – – n – – trivial-rewrite
      bounce unix – – n – 0 bounce
      defer unix – – n – 0 bounce
      trace unix – – n – 0 bounce
      verify unix – – n – 1 verify
      flush unix n – n 1000? 0 flush
      proxymap unix – – n – – proxymap
      proxywrite unix – – n – 1 proxymap
      smtp unix – – n – – smtp
      relay unix – – n – – smtp
      showq unix n – n – – showq
      error unix – – n – – error
      retry unix – – n – – error
      discard unix – – n – – discard
      local unix – n n – – local
      lmtp unix – – n – – lmtp
      anvil unix – – n – 1 anvil
      scache unix – – n – 1 scache
      dovecot unix – n n – – pipe
      flags=DRhu user=vmail:vmail argv=/usr/libexec/dovecot/deliver -f ${sender} -d ${recipient}

      ——————————————–
      DOVECOT CONFIGURATION
      ————————————————————————————————————————————

      # 2.2.10: /etc/dovecot/dovecot.conf
      # OS: Linux 3.10.0-229.20.1.el7.x86_64 x86_64 CentOS Linux release 7.1.1503 (Core) xfs
      auth_mechanisms = plain login
      listen = *
      log_path = /var/log/dovecot.log
      mail_location = maildir:/home/vmail/%d/%n/Maildir
      mail_privileged_group = vmail
      mbox_write_locks = fcntl
      namespace inbox {
      inbox = yes
      location =
      mailbox Drafts {
      special_use = \Drafts
      }
      mailbox Junk {
      special_use = \Junk
      }
      mailbox Sent {
      special_use = \Sent
      }
      mailbox “Sent Messages” {
      special_use = \Sent
      }
      mailbox Trash {
      special_use = \Trash
      }
      prefix =
      }
      passdb {
      args = /etc/dovecot/dovecot-sql.conf.ext
      driver = sql
      }
      service auth-worker {
      user = vmail
      }
      service auth {
      unix_listener /var/spool/postfix/private/auth {
      group = postfix
      mode = 0666
      user = postfix
      }
      unix_listener auth-userdb {
      mode = 0600
      user = vmail
      }
      user = dovecot
      }
      service imap-login {
      inet_listener imap {
      port = 143
      }
      inet_listener imaps {
      port = 993
      ssl = yes
      }
      }
      service lmtp {
      unix_listener /var/spool/postfix/private/dovecot-lmtp {
      group = postfix
      mode = 0600
      user = postfix
      }
      }
      service pop3-login {
      inet_listener pop3 {
      port = 110
      }
      inet_listener pop3s {
      port = 995
      ssl = yes
      }
      }
      ssl = required
      ssl_cert = </etc/pki/dovecot/certs/dovecot.pem
      ssl_key = </etc/pki/dovecot/private/dovecot.pem
      userdb {
      args = uid=vmail gid=vmail home=/home/vmail/%d/%n/Maildir
      driver = static
      }

      ————————————————————————————————————————————————————————————-
      _______________________________________________________________________________________________________________

      Reply
  47. HI,

    Followed exact steps as you have mentioned,
    Sending emails are not an issue but receiving email from other servers is..

    whenever I send email from gmail , I get this response
    —————————————————————————————————————-
    Delivery to the following recipient failed permanently:

    [email protected]

    Technical details of permanent failure:
    Google tried to deliver your message, but it was rejected by the server for the recipient domain example.com by mail.example.com. [1**.**.**.**].

    The error that the other server returned was:
    550 5.1.1 : Recipient address rejected: User unknown in local recipient table
    —————————————————————————————————————-

    And while sending from Yahoo, I get this
    —————————————————————————————————————-
    Sorry, we were unable to deliver your message to the following address.

    :
    Remote host said:
    550 5.1.1 Recipient not found.
    [RCPT_TO]
    —————————————————————————————————————-
    While making an effort in resolving this issue….I have modified main.cf

    Please help me in resolving this issue…

    Reply

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