This is a re-hash of the various guides I’ve made over the years detailing how to setup a virtual mail server (i.e. one that can handle multiple domains/users).
This guide is based on release 2.3 of Postfixadmin. It’s about the only open source project I contribute to regularly – so I ought to at least make an effort and document it 🙂
Requirements:
- Linux Server (Debian, Ubuntu, CentOS, SuSE) or FreeBSD etc
- PostgreSQL or MySQL database
- PHP 5.2.x or greater
- Postfix
- Courier / Cyrus / Dovecot (as appropriate) (I only use Courier, so am of little help with the others).
Postfixadmin Installation
This assumes version 2.3 or above.
dpkg -i postfixadmin-xxxxx.deb
There are also rpm’s around somewhere for SuSE/RH, a port in FreeBSD or you can install from source.
Using the .deb, the database should be created for you, along with some configuration options being filled in within config.inc.php.
- Visit setup.php – it will prompt you to create a setup_password, which needs putting into the config.inc.php file
- After editing config.inc.php, re-visit setup.php and follow it through – this will create the admin user and setup the initial DB structure
- Your database should now be installed
- You may wish to edit other config.inc.php settings (e.g. to turn vacation support on/off or to turn xmlrpc support on/off).
If you perform an upgrade of Postfixadmin in the future, all upgrades to the database should be handled automatically through use of ‘upgrade.php’.
Postfix configuration
There are a few changes that need making to Postfix, firstly – it’s necessary to tell it to use a relational database for various lookups (e.g. aliases and mailboxes); it’s also necessary to configure it to support vacation/auto-reply emails – if you require this functionality.
In my case, I run Postfix on Debian Lenny – other platforms may vary slightly. To attempt at being ‘tidy’ the configuration files for PostgreSQL live in /etc/postfix/pgsql.
(If you’re security concious, especially when you own Daisy slots or any online betting site, then you might want to ensure the database ‘postfix’ user only has read permissions)
Note: I’ve not used the proper alias domains stuff yet – if you wish to use it, check the supplied documentation with Postfixadmin (POSTFIX_CONF.txt)
File: relay_domains.cf
user = postfix
password = something
hosts = localhost
dbname = postfix
query = SELECT domain FROM domain WHERE domain='%s' and backupmx = true
File: virtual_alias_maps.cf
user = postfix
password = something
hosts = localhost
dbname = postfix
query = SELECT goto FROM alias WHERE address='%s' AND active = true
File: virtual_domains_maps.cf
user = postfix
password = something
hosts = localhost
dbname = postfix
#query = SELECT domain FROM domain WHERE domain='%s'
#optional query to use when relaying for backup MX
query = SELECT domain FROM domain WHERE domain='%s' and backupmx = false and active = true
File: virtual_mailbox_limits.cf
# Used for QUOTA!
user = postfix
password = something
hosts = localhost
dbname = postfix
query = SELECT quota FROM mailbox WHERE username='%s'
(Note: I’ve never used quota support, so I can’t guarantee the above is correct)
File: virtual_mailbox_maps.cf
user = postfix
password = something
hosts = localhost
dbname = postfix
query = SELECT maildir FROM mailbox WHERE username='%s' AND active = true
To /etc/postfix/main.cf add the following :
relay_domains = <whatever may have been here before> proxy:pgsql:/etc/postfix/pgsql/relay_domains.cf
virtual_alias_maps = proxy:pgsql:/etc/postfix/pgsql/virtual_alias_maps.cf
virtual_mailbox_domains = proxy:pgsql:/etc/postfix/pgsql/virtual_domains_maps.cf
virtual_mailbox_maps = proxy:pgsql:/etc/postfix/pgsql/virtual_mailbox_maps.cf
virtual_mailbox_base = /var/mail/vmail
virtual_mailbox_limit = 512000000
virtual_minimum_uid = 8
virtual_transport = virtual
virtual_uid_maps = static:8
virtual_gid_maps = static:8
local_transport = virtual
local_recipient_maps = $virtual_mailbox_maps
# this is only needed if you want vacation support -
transport_maps = hash:/etc/postfix/transport
Adding the 'proxy:' to the various lookup lines should improve performance/scalability.
Courier configuration
Courier needs configuring to know how to authorise clients and where to find mailboxes on disk.
/etc/courier/authdaemonrc :
– Enable the appropriate module – e.g.
authmodulelist=”authpgsql”
And then in ‘authpgsqlrc’ contains :
PGSQL_HOST localhost
PGSQL_PORT 5432
PGSQL_USERNAME postfix
PGSQL_PASSWORD something
PGSQL_DATABASE postfix
PGSQL_USER_TABLE mailbox
PGSQL_CRYPT_PWFIELD password
PGSQL_UID_FIELD ‘8’
PGSQL_GID_FIELD ‘8’
PGSQL_LOGIN_FIELD username
PGSQL_HOME_FIELD ‘/var/mail/vmail’
PGSQL_NAME_FIELD name
PGSQL_MAILDIR_FIELD maildir
PGSQL_QUOTA_FIELD quota
(As you can see, I’ve elected to store the mail under /var/mail/vmail with file ownerships set to 8:8. Your installation may differ – but obviously ensure this is kept in sync with Postfix’s main.cf).
This would probably be a good time to test the system to ensure authentication works correctly – create a virtual mailbox through Postfixadmin and tail -f /var/log/mail.log and see if you can login via pop3/imap etc.
SMTP Authentication
This is often useful to allow remote clients to relay through the server – assuming they can prove who they are!
Postfix can use SASL for authentication – this requires SASL to be told to use imap to perform the authentication checks.
File: /etc/sasl/smtpd.conf
pwcheck_method: saslauthd
saslauthd_path: /var/run/saslauthd/mux
log_level: 3
mech_list: PLAIN LOGIN
auxprop_plugin: rimap
On Debian, I have sasl2-bin, libsasl2-modules and libsasl7 packages installed.
You’ll need to edit /etc/default/saslauthd and ensure it has :
OPTIONS=”-c -r -O localhost -m /var/spool/postfix/var/run/saslauthd”
You may also need to explicitly create the above path.
Create /etc/postfix/sasl/smtpd.conf with :
pwcheck_method: saslauthd
saslauthd_path: /var/run/saslauthd/mux
log_level: 3
mech_list: PLAIN LOGIN
auxprop_plugin: rimap
And ensure /etc/postfix/main.cf has :
smtpd_sasl_authenticated_header = yes
smtpd_sasl_auth_enable = yes
smtpd_sasl_security_options = noanonymous
broken_sasl_auth_clients = yes
And smtpd_sender_restrictions contains ‘permit_sasl_authenticated’
Squirrelmail-postfixadmin
If you wish to allow your users to change their passwords/forwarding settings or vacation/auto-reply settings, a postfixadmin plugin is available for squirrelmail (squirrelmail-postfixadmin). You can download it from https://github.com/postfixadmin/postfixadmin/tree/master/ADDITIONS/squirrelmail-plugin
The latest version of the plugin works over XMLRPC and requires very minimal configuration – you’ll need to edit the config file within the plugin to specify the XMLRPC interface URL (http://server/postfixadmin/xmlrpc.php). It’s also necessary to edit the Postfixadmin config.inc.php file to explicitly enable the xmlrpc interface.
Note, when your users go to use the postfixadmin-squirrelmail plugin they will be prompted to enter their mailbox password.
