VHFFS suggests Exim4 SMTP and Courier POP&IMAP software and provides configuration examples for those. Obviously you can use the software you want and use this documentation to help you.

Exim is a Mail Transfer Agent. Exim needs the Exim Heavy daemon on Debian in order to work with PostgreSQL.

Install the following packets:

apt-get install exim4-daemon-heavy

Sample configuration:

/usr/share/doc/vhffs/config/exim4-mx1/exim4.conf

Then:

addgroup --gid 2000 listengine
adduser --uid 2000 --gid 2000 --no-create-home --disabled-login --shell /bin/false --gecos '' listengine
mkdir /data/mail/{,boxes,archives} /data/listengine/{,archives,errors,moderation,public}
chown Debian-exim:Debian-exim /data/mail/boxes
chown listengine:listengine /data/listengine/{archives,errors,moderation}
chmod 700 /data/mail/{boxes,archives} /data/listengine/{archives,errors,moderation}
mv /etc/exim4/exim4.conf{,.orig}
cp /usr/share/doc/vhffs/config/exim4-mx1/exim4.conf /etc/exim4/exim4.conf

And modify /etc/exim4/exim4.conf according to your needs. Then reload exim4.

Courier is the IMAP/POP server used to access mailboxes. It uses the VHFFS databases to check the users, thus it needs a read access to the VHFFS databases.

Install the following packets:

apt-get install courier-authdaemon courier-authlib-postgresql courier-imap courier-imap-ssl courier-pop courier-pop-ssl

In /usr/share/doc/vhffs/config/courier, you will find configuration samples for following Courier files:

• authdaemonrc
• authpgsqlrc
• imapd
• imapd-ssl
• pop3d
• pop3d-ssl

Copy these files into /etc/courier/ and perform the modifications you need in order to access the vhffs database.

Then reload all courier-related softwares.

This is always a good idea to have a backup MX server. A backup MX server is a server that is going to buffer your mails if your primary MX is down (Network outage, hardware failure, configuration error, …).

On your secondary server, install the following packets:

apt-get install exim4-daemon-heavy

Sample configuration:

/usr/share/doc/vhffs/config/exim4-mx2/exim4.conf

Then, you have to duplicate the VHFFS database, you can either use a PostgreSQL replication mechanism or use our mirror script.

After PostgreSQL replication is configured, modify /etc/exim4/exim4.conf according to your needs. Then reload exim4.

Copy the MX2 mirror script in some place.

cp /usr/share/vhffs/backend/mirror/mx2-mirror.pl /usr/local/sbin/
chmod o-rwx /usr/local/sbin/mx2-mirror.pl 
chmod ug+x /usr/local/sbin/mx2-mirror.pl

Create the PostgreSQL secondary database and structures

su - postgres -c "createuser -P mailmx2"
su - postgres -c "createdb -O mailmx2 mailmx2"
psql mailmx2 mailmx2 -h localhost
eximmx2=> \i /usr/share/vhffs/backend/mirror/mx2-mirror.sql

Edit the mx2-mirror.pl script to modify connection fields to both master and slave SQL servers.

Install required dependencies:

apt-get install libdbd-pg-perl

Modify your firewall or anything necessary so that the slave server can connect to the master server.

Then run the mx2-mirror.pl script, it should work

/usr/local/sbin/mx2-mirror.pl

Modify /etc/exim4/exim4.conf to use this database. Then reload exim4.

Of course, you need to run from time to time the mx2-mirror.pl script to update the PostgreSQL database, we let you add the necessary cron entry.