There is a new version of this tutorial available for CentOS 6.3.

Virtual Users And Domains With Postfix, Courier And MySQL (CentOS 5.1) - Page 5

This tutorial exists for these OS versions

On this page

  1. 14 Test Postfix
  2. 15 Populate The Database And Test
  3. 16 References
  4. 17 Links

14 Test Postfix

To see if Postfix is ready for SMTP-AUTH and TLS, run

telnet localhost 25

After you have established the connection to your Postfix mail server type

ehlo localhost

If you see the lines




everything is fine.

[root@server1 ~]# telnet localhost 25
Connected to localhost.localdomain (
Escape character is '^]'.
220 ESMTP Postfix
ehlo localhost
250-SIZE 10240000
250 DSN
221 2.0.0 Bye
Connection closed by foreign host.
[root@server1 ~]#



to return to the system's shell.


15 Populate The Database And Test

To populate the database you can use the MySQL shell:

mysql -u root -p
USE mail;

At least you have to create entries in the tables domains and users:

INSERT INTO `domains` (`domain`) VALUES ('');
INSERT INTO `users` (`email`, `password`, `quota`) VALUES ('', ENCRYPT('secret'), 10485760);

(Please take care you use the ENCRYPT syntax in the second INSERT statement in order to encrypt the password!)

If you want to make entries in the other two tables, that would look like this:

INSERT INTO `forwardings` (`source`, `destination`) VALUES ('', '');
INSERT INTO `transport` (`domain`, `transport`) VALUES ('', '');

To leave the MySQL shell, type


For most people it is easier if they have a graphical front-end to MySQL; therefore you can also use phpMyAdmin (in this example under or to administrate the mail database. Again, when you create a user, go sure that you use the ENCRYPT function to encrypt the password:

I do not think I have to explain the domains and users table further.

The forwardings table can have entries like the following:

source destination Redirects emails for to Creates a Catch-All account for All emails to will arrive at, except those that exist in the users table (i.e., if exists in the users table, mails to will still arrive at @anotherdomain.tld This redirects all emails to to the same user at anotherdomain.tld. E.g., emails to will be forwarded to thomas@anotherdomain.tld., billing@anotherdomain.tld Forward emails for to two or more email addresses. All listed email addresses under destination receive a copy of the email.

The transport table can have entries like these:

domain transport : Delivers emails for locally. This is as if this record would not exist in this table at all. smtp:mail.anotherdomain.tld Delivers all emails for via smtp to the server smtp:mail.anotherdomain.tld:2025 Delivers all emails for via smtp to the server, but on port 2025, not 25 which is the default port for smtp.


The square brackets prevent Postfix from doing lookups of the MX DNS record for the address in square brackets. Makes sense for IP addresses. smtp:mail.anotherdomain.tld Mail for any subdomain of is delivered to mail.anotherdomain.tld.
* smtp:mail.anotherdomain.tld All emails are delivered to mail.anotherdomain.tld. smtp:mail.anotherdomain.tld Emails for are delivered to mail.anotherdomain.tld.


man transport

for more details.

Please keep in mind that the order of entries in the transport table is important! The entries will be followed from the top to the bottom.

Important: Postfix uses a caching mechanism for the transports, therefore it might take a while until you changes in the transport table take effect. If you want them to take effect immediately, run

postfix reload

after you have made your changes in the transport table.


16 References

Tutorial: ISP-style Email Service with Debian-Sarge and Postfix 2.1:

Postfix + Quota:

Mail Passwords Encrypted using saslauthd:


Share this page:

Suggested articles

10 Comment(s)

Add comment



To save others from scratching their heads for so long like i did:

The maildrop rpm included for download in this tutorial is not compiled with mysql support! If you wish to use maildrop with the setup described here you will need to build your own maildrop rpm according to the instructions here:



This is a really good setup, but if you add greylisting it cuts down substantially more spam.

There is lots of doc around about greylisting, so make your own mind up about the best tool and method, but is really easy to follow and gets you going in minutes.

Highly Recommended as an addition to this howto...


Great article, and the best one I have found so far. 
However,I think that something is missing from the current tutorial (information about setting up maildir). I was getting some directory issues when i telneted on port 143. Then I realized that had to do a maildirmake on /home/vmail/[domain]/user to create the mailbox , then after that it worked just fine. My question now is : will i have to do that for every user? I thought there was a routine that would automatically create the directory after i add a user to the database.

Thanks again for this Article.


The following script in /etc/maildroprc will create the users maildir mailboxes automatically and it will also automatically filter anything marked as SPAM to the users' .Junk/ mail folder.


# commands and variables for making the mail directories

# make the user's mail directory if it doesn't exist
`test -e $MAILDIR`
if ($RETURNCODE != 0)
 `$mkdir -p $MAILDIR`
 `$rmdir $MAILDIR`
 `$maildirmake $MAILDIR`

# make the .Junk folder if it doesn't exist
`test -d $_JUNK_DEST`
if ($RETURNCODE != 0 )
 `$maildirmake $_JUNK_DEST`
 #auto subscribe. the following works for courier-imap
 `echo INBOX.Junk >> $MAILDIR/courierimapsubscribed`

if (/^X-Spam-Flag:.*YES/)
    exception {
        to $DEFAULT/.Junk/

From: tccom

great tutorial Falko,

 this post is to remember all that if you want to use maildrop as local delivery system, the following line must be inserted into "transport" table of our mysql database 'mail':


 and then you can customize maildrop with /etc/maildroprc



From: Anonymous

Hi all.

I'd like to know if this kind of configuration can work with roundcube webclient. If yes, is there any guide or how to marge this configuration with roundcube?

 My problem is that i cant find any link between postfix and roundcube's database. Any advice? Where can i start to work on?

Many thx

P.S.: wonderful guide :)

From: Britto


Roundcube is just a webclient  and you should be able to integrate with roundcube.That is nothing to do with this guide and I could be able to do that .

Everything goes well as per this tutorial other than this version of postfix duplicates the mail for multi recipient inboxes. 








From: Anonymous

Can someone give us some hits how to integrate Roundcube with this setup? Where is the link between the 2 databases?

From: Eugene Frakt

You don't have to link the databases to use Roundcube.  It connects to the mailbox with standard imap, so all you have to do is input the imap settings in the Roundcube config.

From: Anonymous

Hello. I installed postfix & courier as this HOWTO describes. I also installed Horde/IMP and configured it to use courier at localhost as an IMAP server. I added domains & users to the MySQL table, however, I kept getting authentication errors when logging into Horde. In /var/log/maillog, there were error messages like:

Mar 17 23:33:53 hostname imapd: chdir No such file or directory

(I've changed the hostname and domain name in the example above, but otherwise that is a cut-and-paste from my log file).

Turns out, the solution was that the directory it's looking for in /home/vhosts isn't created until after the account receives it's first email. It wasn't until after I'd sent a test message (via smtp a.k.a. port 25) to that IMAP logins were sucessful.

Hope this saves somebody some grief.