Truedoc

h1. A mail server with Postfixadmin, Postfix and Dovecot on Debian Lenny

This HOWTO will explain the installation and configuration of a full featured mail server using _Postfix_ as SMTP server, _Dovecot_ as POP/IMAP server and _Postfixadmin_ as management interface. As _Postfixadmin_ need a database to maintain account and domain informations we will use _MySQL_ (but also _PostgresSQL_ or _SQLite_ can be used). All the configurations were done on a _Debian Lenny_ system.

h2. Postfixadmin Installation

Postfixadmin is distributed as Debian package directly by the maintainer, but we need to download just the @.deb@ file from "here":http://sourceforge.net/project/showfiles.php?group_id=191583&package_id=225300 because there is no repository. Before installing it we will need to install some dependencies (a web server, and because we want to use it on a standalone server, also a database server). We choose to use Apache as web server and MySQL as database server, so we will need to install these packages and all the other _Postfixadmin_ dependencies; this can be done the Debian way with the command: 

<pre>

aptitude install dbconfig-common wwwconfig-common  \

      libapache2-mod-php5 php5 php5-imap php5-mysql \

      mysql-client mysql-server postfix-mysql

</pre>

we will also have to answer to the ordinary setup questions made by _debconf_; we can just accept the default values, but we will have to choose a password for the _MySQL_ root administrative account.

Before installing the Postfixadmin from the @.deb@ file we will need to create a database and a database account that will be used by _Postfixadmin_ for its data; we can do this with the following commands: 

<pre>

mysqladmin -u root -p create postfixadmin

mysql -u root -p

mysql> grant create, select, insert, update, delete, lock, index, alter, drop 

             on postfixadmin.* to 'postfixadmin'@'localhost' 

             identified by 'secretandcomplexpassword';

mysql> flush privileges;

mysql> \q

</pre>

(they will ask for the root account password that was given in the previous step). After this we can install the @.deb@ file with:

<pre>

dpkg -i postfixadmin_*.deb 

</pre>

There are two possible choices for Postfixadmin: the 2.2 stable version and the new 2.3 release candidate; this last one supports more features and is almost production ready. If you use the 2.2 stable version you will need to modify the following lines of the @/etc/postfixadmin/config.inc.php@ file to setup the access to the previously created database: 

<pre>

$CONF['configured'] = true;

...

$CONF['database_type'] = 'mysql';

$CONF['database_host'] = 'localhost';

$CONF['database_user'] = 'postfixadmin';

$CONF['database_password'] = 'secretandcomplexpassword';

$CONF['database_name'] = 'postfixadmin';

</pre>

If instead you use the 2.3 development version, having @dbconfig-common@ and @wwwconfig-common@ installed, the previous step of the database creation is managed by the package itself and it is no more needed. Also the database access configuration inside @/etc/postfixadmin/config.inc.php@ is automatically done by _debconf_, so all is needed is to give to debconf the password of the MySQL root user that you setup at the beginning, and then answer to the _debconf_ questions about the password used for the Postfixadmin dedicated database user. 

After this we can proceed to populate the database, this will be done by Postfixadmin itself using the following link in a browser (we can use the same link for database upgrade when installing a new Postfixadmin version, or to reset the Postfixadmin superuser password):

<pre>

http://MY.POSTFIXADMIN.SERVER.IP/postfixadmin/setup.php

</pre>

Up to 2.2 version this PHP script should be run once, and then removed after its use. With the 2.3 version when it is used for the first time it would ask for a setup password, and then print an hashed value that must be put inside @/etc/postfixadmin/config.inc.php@; the browser will show the line that should replace this one: 

<pre>

$CONF['setup_password'] = 'changeme';

</pre>

With this modification done we can re-execute the script going back to @http://MY.POSTFIXADMIN.SERVER.IP/postfixadmin/setup.php@; this time can use the setup password to create an administrative Postfixadmin account having full access to all management functions. It should be noted that like all Postfixadmin accounts also this one should be given in the form of an email address (i.e. something like @admin@mydomain.it@). 

To check if this initial setup has been completed successfully we can see if everything is working fine going to the @http://MY.POSTFIXADMIN.SERVER.IP/postfixadmin@ address and logging in using the superuser account we just created. After this check we can proceed doing some more specific configuration; the first one is to put proper references to our main domain in the web interface; this can be done with the following commands: 

<pre>

cd /etc/postfixadmin/

mv config.inc.php config.inc.php.orig

sed -e 's/change-this-to-your.domain.tld/mydomain.it/g' config.inc.php.orig > config.inc.php

</pre>

and to be sure we can check the file to see if all link to web pages are correct (they will be always something like @http://mydomain.it@).

An important step is to configure the mailbox pathname that will be used by both Postfix and Dovecot, we choose to map an email account like @username@mydomain.it@) to a mailbox pathname like @mydomain.it/username@, to do this we have to put the following configuration values in the @/etc/postfixadmin/config.inc.php@ file: 

<pre>

$CONF['domain_path'] = 'YES';

$CONF['domain_in_mailbox'] = 'NO';

</pre>

Then to enable quotas we will need to modify also the following line:

<pre>

$CONF['quota'] = 'YES';

</pre>

and to enable the @vacation@ support we will need to modify the following lines: 

<pre>

$CONF['vacation'] = 'YES';

$CONF['vacation_domain'] = 'autoreply.mydomain.it'

</pre>

where @autoreplay.mydomain.it@ is the domain used by Postfix to manage @vacation@ email (we'll look at this in the following). 

Other configuration lines that can be modified are the following:

<pre>

$CONF['default_language'] = 'it';

$CONF['min_password_length'] = 6;

$CONF['aliases'] = '50';

$CONF['mailboxes'] = '50';

$CONF['maxquota'] = '50';

</pre>

respectively to setup the web interface language, a minimum length for the accounts password, and the default values for limit on number of alias, mailbox and megabytes for the quota. These last three will be proposed by the management interface when creating a new domain (a 0 means no limit).

The Postfixadmin 2.3 version has a new simplified management for having the same aliases on more than on domain; this new feature need more database queries and a modified Postfix configuration, so if not needed is better to disable it; this can be done with the following line:

<pre>

$CONF['alias_domain'] = 'NO';

</pre>

To check if everything is working fine we can login as administrator in the web interfaces to create a new domain and some user accounts. Then we can logout and check if that those account are working by re-logging as that users. 

h2. Postfix configuration

Having user account and domain data managed by Postfixadmin, we need to configure Postfix virtual mailbox according to the data stored in MySQL. The first step is to create a base directory where to put all the virtual mailboxes; we will also need a system user that will own all the files. We can do this with the following commands:

<pre>

mkdir /var/mail/vmail

useradd -d /var/mail/vmail vmail

chown vmail:vmail /var/mail/vmail/

chmod o-xr /var/mail/vmail/

</pre>

We also need to avoid the use of procmail as LDA so we will need to comment the following standard line in ad Debian installed Postfix configuration:

<pre>

#mailbox_command = procmail -a "$EXTENSION"

</pre>

Then we need to setup Postfix to use virtual mailboxes getting the informations about users, domain and pathnames from the database; this can be done adding the following lines to @/etc/postfix/main.cf@: 

<pre>

virtual_alias_maps = proxy:mysql:/etc/postfix/mysql_virtual_alias_maps.cf

virtual_mailbox_domains = proxy:mysql:/etc/postfix/mysql_virtual_domains_maps.cf

virtual_mailbox_maps = proxy:mysql:/etc/postfix/mysql_virtual_mailbox_maps.cf

virtual_mailbox_base = /var/mail/vmail

virtual_minimum_uid = 106

virtual_transport = virtual

virtual_uid_maps = static:106

virtual_gid_maps = static:61

</pre>

where 106 e 61 are the numeric _uid_ and _gid_ for the @vmail@ user (these number can be different in each system so you have to check them yourself with something like @getent passwd|grep vmail@).

After this we need to create all @the mysql_*@ files to tell Postfix how to access to the database to get the information it needs. The first file, @mysql_virtual_alias_maps.cf@, configure the access to aliases definitions and it should be something like: 

<pre>

user = postfixadmin

password = secretandcomplexpassword

hosts = localhost

dbname = postfixadmin

query = SELECT goto FROM alias WHERE address='%s' AND active = 1

</pre>

the second file, @mysql_virtual_domains_maps.cf@, configure the access to domain definitions, and it should be something like: 

<pre>

user = postfixadmin

password = secretandcomplexpassword

hosts = localhost

dbname = postfixadmin

query = SELECT domain FROM domain WHERE domain='%s' and backupmx = '0' and active = '1'

</pre>

the third file, @mysql_virtual_mailbox_maps.cf@, configure the access to mailbox pathname (relative to the base directory @/var/mail/vmail@), and it should be something like: 

<pre>

user = postfixadmin

password = secretandcomplexpassword

hosts = localhost

dbname = postfixadmin

query = SELECT maildir FROM mailbox WHERE username='%s' AND active = 1

</pre>

If we want to use Postfixadmin to manage secondary mail server for some domains we will need to add to @/etc/postfix/main.cf @also the following line: 

<pre>

relay_domains = $mydestination, proxy:mysql:/etc/postfix/mysql_relay_domains_maps.cf

</pre>

where @mysql_relay_domains_maps.cf@ should be something like: 

<pre>

user = postfixadmin

password = secretandcomplexpassword

hosts = localhost

dbname = postfixadmin

query = SELECT domain FROM domain WHERE domain='%s' and backupmx = '1' and active = '1'

</pre>

Because these files contains a clean text password they must be unreadable by anyone, so at least verify that they have right permissions or otherwise set them with:

<pre>

chgrp postfix /etc/postfix/mysql_*

chmod 640 /etc/postfix/mysql_*

</pre>

To check if everything is working fine you can send an email to an user you previously created with Postfixadmin and check the @/var/log/mail.log@ file to see if it is accepted. 

h2. Postfix/Postfixadmin vacation configuration

If we want to manage _vacation_ trough _Postfixadmin_ we need some additional Postfix configurations. As first step we need a system user dedicated to the automatic answer management, with the lowest possible privileges; we can create it with the following commands: 

<pre>

groupadd -g 65501 vacation

useradd -g 65501 -u 65501 -c Vacation -s /sbin/nologin -d /nonexistent vacation

</pre>

then we will need a directory for temporary files accessible only for this user, we can create it with the following commands:

<pre>

mkdir /var/spool/vacation

chown -R vacation.vacation /var/spool/vacation

chmod o-xr /var/spool/vacation 

</pre>

The second step is to setup the _vacation_ script, we need to put a copy (it's distributed with Postfixadmin) in the previous directory; this can be done with the following commands:

<pre>

cd /usr/share/doc/postfixadmin/examples/VIRTUAL_VACATION/

zcat vacation.pl.gz > /var/spool/vacation/vacation.pl

chmod 700 /var/spool/vacation/vacation.pl

chown vacation.vacation /var/spool/vacation/vacation.pl

</pre>

to have the script working correctly we will also need some Perl modules; these can be installed with the command:

<pre>

aptitude install libemail-valid-perl libmime-encwords-perl libmime-perl \

         libmail-sender-perl liblog-log4perl-perl

</pre>

and at last we will need to setup the script to access to the database, this can be done modifying the following lines at the beginning of it (note that we are using the same values used in the Postfixadmin configuration):

<pre>

our $db_type = 'mysql';

our $db_host = 'localhost';

our $db_username = 'postfixadmin';

our $db_password = 'secretandcomplexpassword';

our $db_name     = 'postfixadmin';

our $vacation_domain = 'autoreply.mydomain.it';

</pre>

The last step is the Postfix configuration; we will need to setup a new transport dedicates to _vacation_, so we need to add to @/etc/postfix/master.cf@ the following lines: 

<pre>

vacation    unix  -       n       n       -       -       pipe

  flags=Rq user=vacation argv=/var/spool/vacation/vacation.pl -f ${sender} -- ${recipient}

</pre>

then we will need to use this transport for all mail directed to the dedicated @autoreply.mydomain.it@ domain, so first we need to create the @/etc/postfix/transport@ file with the following line: 

<pre>

autoreply.mydomain.it       vacation:

</pre>

and then add to @/etc/postfix/main.cf@ the following line:

<pre>

transport_maps = hash:/etc/postfix/transport

</pre>

This done we can tell Postfix to use the new configuration with the following commands:

<pre>

postmap /etc/postfix/transport

postfix reload

</pre>

h2. Dovecot configuration

To make emails available to the users we well need a POP/IMAP server, we choose to use Dovecot, so we will need to install it, we will do the Debian way with the following command (we will install @ntp@ also, that is needed because Dovecot could have problem if time is moving backwards): 

<pre>

aptitude install dovecot-imapd dovecot-pop3d ntp

</pre>

then we will need to tell Dovecot where to find the emails and how to authenticate users. 

The first step is to modify the default configuration to access to the @/var/mail/vmail@ directory as the user @vmail@, having mailbox in the form @mydomain.it/username@; this can be done putting the following lines in @/etc/dovecot/dovecot.conf@: 

<pre>

mail_location = maildir:/var/mail/vmail/%d/%n

mail_privileged_group = vmail

first_valid_uid = 106

</pre>

where 106 is the @vmail@ _uid_ (as before this could be different on different installations).

The second step is to enable the user authentication over the MySQL data, this can be done removing the default PAM configuration for the @userdb@ and @passdb@ directives, putting instead something like the following in @/etc/dovecot/dovecot.conf@: 

<pre>

  passdb sql {

    args = /etc/dovecot/dovecot-mysql.conf

  }

  userdb sql {

    args = /etc/dovecot/dovecot-mysql.conf

  }

</pre>

then we will need to create the file @/etc/dovecot/dovecot-mysql.conf@ to tell Dovecot how to access to the database; it should be something like: 

<pre>

driver = mysql

connect = host=localhost dbname=postfixadmin user=postfixadmin password=secretandcomplexpassword client_flags=0

default_pass_scheme = MD5

user_query = SELECT maildir, 106 AS uid, 61 AS gid FROM mailbox WHERE username = '%u'

password_query = SELECT password FROM mailbox WHERE username = '%u' AND active = '1' 

</pre>

where 106 and 61 are respectively the _uid_ and _gid_ of the user @vmail@. 

To check if everything is working fine you can connect to the server with an email client and look at the email you previously sent. 

h2. Authenticated SMTP

This will be provided by telling _Postfix_ to use _Dovecot_ as authentication provider. The first step is to setup Dovecot to provide an authentication socket for Postfix; this can be done by adding the following lines to @/etc/dovecot/dovecot.conf@: 

<pre>

socket listen {

        client {

        path = /var/spool/postfix/private/auth

        mode = 0660

        user = postfix

        group = postfix

        }

}

</pre>

to consent access to broken client like Outlook, you will need also to modify the mechanism line in @/etc/dovecot/dovecot.conf@ as in the following:

<pre>

auth default {

   ...

   mechanisms = plain login

   ...

}

</pre>

after restarting Dovecot this will create the socket in the Postfix chroot as @private/auth@, and it should look like this: 

<pre>

# ls /var/spool/postfix/private/auth -l

srw-rw---- 1 postfix postfix 0 29 set 18:59 /var/spool/postfix/private/auth

</pre>

The second step is to configure Postfix to use this socket, this will be done adding the following lines to @/etc/postfix/main.cf@: 

<pre>

smtpd_sasl_type = dovecot

smtpd_sasl_path = private/auth

</pre>

The rest is just the ordinary Postfix configuration needed to accept SASL authenticated sessions, forcing them to be done using TLS for security, so you will need to enable SASL authentication under TLS adding the following lines to @/etc/postfix/main.cf@: 

<pre>

smtpd_sasl_auth_enable = yes

smtp_sasl_application_name = smtpd

smtpd_sasl_local_domain = $myhostname

broken_sasl_auth_clients = yes

</pre>

and force use of TLS:

<pre>

smtpd_use_tls = yes

smtpd_tls_auth_only = yes

smtpd_tls_loglevel = 1

smtpd_tls_received_header = yes

smtpd_tls_session_cache_timeout = 3600s

tls_random_source = dev:/dev/urandom

</pre>

and then give relay permission to authenticated users adding the line @permit_sasl_authenticated@ to the @smtpd_recipient_restrictions parameter@, that should look like: 

<pre>

smtpd_recipient_restrictions =

        permit_mynetworks,

        permit_sasl_authenticated,

        reject_rbl_client zen.spamhaus.org,

        reject_non_fqdn_sender,

        reject_non_fqdn_recipient,

        reject_unknown_sender_domain,

        reject_unauth_destination

</pre>

h2. CLI script for massive account creation

_Postfixadmin_ is a very nice web interface to manage email accounts and domain, but like all GUI or web based interfaces using it is not so practical when you have to create hundreds of accounts in a single shot. For this reason we developed a simple Python script that will do mass account creation. You can find it in the attachment. 

The script is quite easy to use, it just need a CSV file with the account list; it should work with any kind of CSV file, but it was tested just with the default output of OpenOffice.org Calc. The first line of the file should contains the column names, the script will look only to columns named user, domain, password and name (case sensitive!); they will have the meaning explained in the following table: 

|_.Parametro|_.Significato|

| user     | user part of the email (like user in @user@domain.com@)

| password | cleartext password

| domain   | domain name (like '@domain.com@')

| name     | full user name ('Name Surname')

It's only needed to provide at least the user, domain and password columns, and the script will fill the database tables creating accounts and domains. The email accounts will be in the form @user@domain@, with password password for each line present in the CSV file. It will also create all domains present in the file and, if the @-A@ option is given, also the default accounts (@abuse@, @hostmaster@, @postmaster@, @webmaster@) for each domain.

The script requires a single argument, the name of the CSV file, and the @-p@ option followed by the database access password (i.e., following the previous instructions, "secretandcomplexpassword"). There are some more option to set database name, database user name, database host, etc. but the default values should be good because they are the same used by the default installation of Postfixadmin. The whole list of options can be printed executing the script without arguments or with the @-h@ option. 

The script doesn't do data validation, so it is published without any warranty (under the GPL licence). This means that making a database backup before using it is strongly suggested. It will print errors if some accounts or domains are already present in the database, skipping creation (i.e. it will not overwrite them), but it will create all other accounts and domains not already present. It will also skip the creation of a duplicated account.