Virtual Users And Domains With Postfix, Courier, MySQL And SquirrelMail (CentOS 6.2 x86_64) - Page 5

13 Install Razor, Pyzor And DCC And Configure SpamAssassin

Razor, Pyzor and DCC are spamfilters that use a collaborative filtering network. To install Razor and Pyzor, run

yum install perl-Razor-Agent pyzor

Then initialize both services:

chmod -R a+rX /usr/share/doc/pyzor-0.5.0 /usr/bin/pyzor /usr/bin/pyzord
chmod -R a+rX /usr/lib/python2.6/site-packages/pyzor
su -m amavis -c 'pyzor --homedir /var/spool/amavisd discover'
su -m amavis -c 'razor-admin -home=/var/spool/amavisd -create'
su -m amavis -c 'razor-admin -home=/var/spool/amavisd -register'

Then we install DCC as follows:

cd /tmp
wget http://www.dcc-servers.net/dcc/source/dcc-dccproc.tar.Z
tar xzvf dcc-dccproc.tar.Z
cd dcc-dccproc-1.3.141
./configure --with-uid=amavis
make
make install
chown -R amavis:amavis /var/dcc
ln -s /var/dcc/libexec/dccifd /usr/local/bin/dccifd

Now we have to tell SpamAssassin to use these three programs. Edit /etc/mail/spamassassin/local.cf so that it looks like this:

vi /etc/mail/spamassassin/local.cf

# These values can be overridden by editing ~/.spamassassin/user_prefs.cf
# (see spamassassin(1) for details)

# These should be safe assumptions and allow for simple visual sifting
# without risking lost emails.

#required_hits 5
#report_safe 0
#rewrite_header Subject [SPAM]

# dcc
use_dcc 1
dcc_path /usr/local/bin/dccproc

#pyzor
use_pyzor 1
pyzor_path /usr/bin/pyzor

#razor
use_razor2 1
razor_config /var/spool/amavisd/razor-agent.conf

#bayes
use_bayes 1
use_bayes_rules 1
bayes_auto_learn 1

Then we must enable the DCC plugin in SpamAssassin. Open /etc/mail/spamassassin/v310.pre and uncomment the loadplugin Mail::SpamAssassin::Plugin::DCC line:

vi /etc/mail/spamassassin/v310.pre

[...]
# DCC - perform DCC message checks.
#
# DCC is disabled here because it is not open source. See the DCC
# license for more details.
#
loadplugin Mail::SpamAssassin::Plugin::DCC
[...]

You can check your SpamAssassin configuration by executing:

spamassassin --lint

It shouldn't show any errors.

Run

/etc/init.d/amavisd restart

afterwards.

Now we update our SpamAssassin rulesets as follows:

sa-update --no-gpg

We create a cron job so that the rulesets will be updated regularly. Run

crontab -e

to open the cron job editor. Create the following cron job:

23 4 */2 * * /usr/bin/sa-update --no-gpg &> /dev/null

This will update the rulesets every second day at 4.23h.

 

14 Quota Exceedance Notifications

If you want to get notifications about all the email accounts that are over quota, then create the file /usr/local/sbin/quota_notify:

cd /usr/local/sbin/
vi quota_notify

#!/usr/bin/perl -w

# Author <jps@tntmax.com>
#
# This script assumes that virtual_mailbox_base in defined
# in postfix's main.cf file. This directory is assumed to contain
# directories which themselves contain your virtual user's maildirs.
# For example:
#
# -----------/
#            |
#            |
#    home/vmail/domains/
#        |          |
#        |          |
#  example.com/  foo.com/
#                   |
#                   |
#           -----------------
#           |       |       |
#           |       |       |
#         user1/   user2/  user3/
#                           |
#                           |
#                        maildirsize
#

use strict;

my $POSTFIX_CF = "/etc/postfix/main.cf";
my $MAILPROG = "/usr/sbin/sendmail -t";
my $WARNPERCENT = 80;
my @POSTMASTERS = ('postmaster@domain.tld');
my $CONAME = 'My Company';
my $COADDR = 'postmaster@domain.tld';
my $SUADDR = 'postmaster@domain.tld';
my $MAIL_REPORT = 1;
my $MAIL_WARNING = 1;

#get virtual mailbox base from postfix config
open(PCF, "< $POSTFIX_CF") or die $!;
my $mboxBase;
while (<PCF>) {
   next unless /virtual_mailbox_base\s*=\s*(.*)\s*/;
   $mboxBase = $1;
}
close(PCF);

#assume one level of subdirectories for domain names
my @domains;
opendir(DIR, $mboxBase) or die $!;
while (defined(my $name = readdir(DIR))) {
   next if $name =~ /^\.\.?$/;        #skip '.' and '..'
   next unless (-d "$mboxBase/$name");
   push(@domains, $name);
}
closedir(DIR);
#iterate through domains for username/maildirsize files
my @users;
chdir($mboxBase);
foreach my $domain (@domains) {
        opendir(DIR, $domain) or die $!;
        while (defined(my $name = readdir(DIR))) {
           next if $name =~ /^\.\.?$/;        #skip '.' and '..'
           next unless (-d "$domain/$name");
      push(@users, {"$name\@$domain" => "$mboxBase/$domain/$name"});
        }
}
closedir(DIR);

#get user quotas and percent used
my (%lusers, $report);
foreach my $href (@users) {
   foreach my $user (keys %$href) {
      my $quotafile = "$href->{$user}/maildirsize";
      next unless (-f $quotafile);
      open(QF, "< $quotafile") or die $!;
      my ($firstln, $quota, $used);
      while (<QF>) {
         my $line = $_;
              if (! $firstln) {
                 $firstln = 1;
                 die "Error: corrupt quotafile $quotafile"
                    unless ($line =~ /^(\d+)S/);
                 $quota = $1;
            last if (! $quota);
            next;
         }
         die "Error: corrupt quotafile $quotafile"
            unless ($line =~ /\s*(-?\d+)/);
         $used += $1;
      }
      close(QF);
      next if (! $used);
      my $percent = int($used / $quota * 100);
      $lusers{$user} = $percent unless not $percent;
   }
}

#send a report to the postmasters
if ($MAIL_REPORT) {
   open(MAIL, "| $MAILPROG");
   select(MAIL);
   map {print "To: $_\n"} @POSTMASTERS;
   print "From: $COADDR\n";
   print "Subject: Daily Quota Report.\n";
   print "DAILY QUOTA REPORT:\n\n";
   print "----------------------------------------------\n";
   print "| % USAGE |            ACCOUNT NAME          |\n";
   print "----------------------------------------------\n";
   foreach my $luser ( sort { $lusers{$b} <=> $lusers{$a} } keys %lusers ) {
      printf("|   %3d   | %32s |\n", $lusers{$luser}, $luser);
      print "---------------------------------------------\n";
   }
        print "\n--\n";
        print "$CONAME\n";
        close(MAIL);
}

#email a warning to people over quota
if ($MAIL_WARNING) {
        foreach my $luser (keys (%lusers)) {
           next unless $lusers{$luser} >= $WARNPERCENT;       # skip those under quota
           open(MAIL, "| $MAILPROG");
           select(MAIL);
           print "To: $luser\n";
      map {print "BCC: $_\n"} @POSTMASTERS;
           print "From: $SUADDR\n";
           print "Subject: WARNING: Your mailbox is $lusers{$luser}% full.\n";
           print "Reply-to: $SUADDR\n";
           print "Your mailbox: $luser is $lusers{$luser}% full.\n\n";
           print "Once your e-mail box has exceeded your monthly storage quota\n";
      print "your monthly billing will be automatically adjusted.\n";
      print "Please consider deleting e-mail and emptying your trash folder to clear some space.\n\n";
           print "Contact <$SUADDR> for further assistance.\n\n";
           print "Thank You.\n\n";
           print "--\n";
           print "$CONAME\n";
           close(MAIL);
        }
}

Make sure that you adjust the variables at the top (especially the postmaster@domain.tld email address).

We must make the file executable:

chmod 755 quota_notify

Run

crontab -e

to create a cron job for that script:

0 0 * * * /usr/local/sbin/quota_notify &> /dev/null

 

15 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

250-STARTTLS

and

250-AUTH PLAIN LOGIN

everything is fine.

[root@server1 sbin]# telnet localhost 25
Trying ::1...
Connected to localhost.
Escape character is '^]'.
220 server1.example.com ESMTP Postfix

<-- ehlo localhost
250-server1.example.com
250-PIPELINING
250-SIZE 10240000
250-VRFY
250-ETRN
250-STARTTLS
250-AUTH PLAIN LOGIN
250-AUTH=PLAIN LOGIN
250-ENHANCEDSTATUSCODES
250-8BITMIME
250 DSN

<-- quit
221 2.0.0 Bye
Connection closed by foreign host.
[root@server1 sbin]#

Type

quit

to return to the system's shell.

 

16 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 ('example.com');
INSERT INTO `users` (`email`, `password`, `quota`) VALUES ('sales@example.com', 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 ('info@example.com', 'sales@example.com');
INSERT INTO `transport` (`domain`, `transport`) VALUES ('example.com', 'smtp:mail.example.com');

To leave the MySQL shell, type

quit;

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 http://192.168.0.100/phpMyAdmin/ or http://server1.example.com/phpMyAdmin/) 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  
info@example.com sales@example.com Redirects emails for info@example.com to sales@example.com
@example.com thomas@example.com Creates a Catch-All account for thomas@example.com. All emails to example.com will arrive at thomas@example.com, except those that exist in the users table (i.e., if sales@example.com exists in the users table, mails to sales@example.com will still arrive at sales@example.com).
@example.com @anotherdomain.tld This redirects all emails to example.com to the same user at anotherdomain.tld. E.g., emails to thomas@example.com will be forwarded to thomas@anotherdomain.tld.
info@example.com sales@example.com, billing@anotherdomain.tld Forward emails for info@example.com 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  
example.com : Delivers emails for example.com locally. This is as if this record would not exist in this table at all.
example.com smtp:mail.anotherdomain.tld Delivers all emails for example.com via smtp to the server mail.anotherdomain.com.
example.com smtp:mail.anotherdomain.tld:2025 Delivers all emails for example.com via smtp to the server mail.anotherdomain.com, but on port 2025, not 25 which is the default port for smtp.
example.com

smtp:[1.2.3.4]
smtp:[1.2.3.4]:2025
smtp:[mail.anotherdomain.tld]

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

See

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.

 

17 Send A Welcome Email For Creating Maildir

When you create a new email account and try to fetch emails from it (with POP3/IMAP) you will probably get error messages saying that the Maildir doesn't exist. The Maildir is created automatically when the first email arrives for the new account. Therefore it's a good idea to send a welcome email to a new account.

First, we install the mailx package:

yum install mailx

To send a welcome email to sales@example.com, we do this:

mailx sales@example.com

You will be prompted for the subject. Type in the subject (e.g. Welcome), then press ENTER, and in the next line type your message. When the message is finished, press ENTER again so that you are in a new line, then press CTRL+D:

[root@server1 ~]# mailx sales@example.com
Subject: Welcome
<-- ENTER
Welcome! Have fun with your new mail account. <-- ENTER
<-- CTRL+D
EOT
[root@server1 ~]#

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14 Comment(s)

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Comments

From: Habeeb at: 2012-02-01 23:21:14

Dear Admin,

 I am getting this below error while building the rpm for postfix, so please advice what i should now??? Still i am in the first page.

 

[root@example SPECS]# rpmbuild -ba postfix.spec
error: Name field must be present in package: (main package)
error: Version field must be present in package: (main package)
error: Release field must be present in package: (main package)
error: Summary field must be present in package: (main package)
error: License field must be present in package: (main package)
[root@example SPECS]#
 

From: Arash S. at: 2012-03-20 12:45:46

Hi there,

the download address for epel has been changed. it is: "http://download3.fedora.redhat.com/pub/epel/6/i386/epel-release-6-5.noarch.rpm"

Thanks,

A.

From: Anonymous at: 2013-03-21 10:28:48

 "epel-release-6-5.noarch.rpm" is not there / anymore. 

Try this instead: 

wget http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm

 

From: Hillary John at: 2012-05-22 20:53:08

http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-6.noarch.rpm

 

From: Skaroth at: 2012-07-21 14:08:45

Thank you for this great tutorial. Perfectly written!

From: Alberto at: 2012-09-27 14:40:01

Hello.

 Thanks for this great HowTo.

 I´m trying to adapt this installation to use with  postfixadmin, but i´m having a lot of problems, could anybody let a link to a HowTo or something like that?

 

Thanks a lot.

From: dusko at: 2012-03-01 16:21:23

Hello,

Thank you for a really useful guide!

I'm wondering what changes would be needed to use ViMbAdmin to administrate mail server created in this guide?

On https://github.com/opensolutions/ViMbAdmin/wiki/Postfix-and-MySQL-Integration I've found general instructions for the integration.

I suppose in ViMbAdmin integration guide that mail store is Maildir or mbox, not the mysql database.

Finally, is ISPConfig3 better solution then  ViMbAdmin?

From: Silent at: 2012-03-17 00:17:23

You forgot to install the cyrus-sasl-plain Package in your Guide.

it doesn't show till you actually try postfix in step 15, where it will continuously fail because it cannot find any SASL Authentication mechanisms.


From: Sandeep Rohilla at: 2012-02-02 12:12:05

Hi, Document is good, but i am not able to send and receive mails one more thing when i try to login with webmail, its show ERROR: Connection dropped by IMAP server.

and i am not able to connect with mail client also it - shows not able to connect and showing password or userid incorrect  

Please help me 

From: at: 2012-08-28 10:01:28

@ 3 above comments,

 To "enable" a mailbox, first send a mail to it. it will create the folders and after you will be able to connect to imap.

From: Sandeep Rohilla at: 2013-03-30 11:28:19

Hi,

I resolved it by changing the permissions and username of mysql in configuration file. But i just wanted to know 2 things. I am trying to make a mailserver replica, so that if one is down it automatically switch to 2nd one. what package i will use to do so. one more thing if i want to make a backup copy of my server running on different IP  and diffrent FQDN name. Can I use the backup server by changing the IP and FQDN name? Do i need to regenerate all the certificates?

From: Anonymous at: 2013-04-22 03:41:56

Hi Sandeep..

Im also facing same problem. "Connection dropped by IMAP server". But im not able to understand what exactly u have mentioned. Resolved by "changing permissions and username of mysql"

Can u make it clear..

 

Regards

Dev

From: at: 2012-03-16 13:39:28

i doesn't crate the folders in /home/vmail

ERROR: ERROR: Could not complete request.
Query: SELECT "INBOX"
Reason Given: Unable to open this mailbox.

 

ERROR: ERROR: Connection dropped by IMAP server.
Query: SUBSCRIBE "INBOX.Sent"

From: mac at: 2012-06-02 11:23:38

Hi,

   Your tutorial is good, But when i am try to login through webmail  its shows error as ERROR: Connection dropped by IMAP server. and when checked the log file server imapd: chdir test.co/test/: No such file or directory and in next line server imapd: test@test.co: No such file or directory but when i tried the authtest -s imap test@test.co 12345 authenticatied sucessfullly.

Please help me...