= Prerequisites =

Depending on the mail transport agent (MTA) chosen, the following packages are
required for this software to work on Debian systems:

 Exim::    exim4-daemon-heavy
 Postfix:: postfix postfix-ldap

The software itself requires the following packages:

 Python::  python
 pytz::    python-tz

If the [[../DatabaseStore|database store]] is used, the following packages are required:

 PostgreSQL:: postgresql-9.4 (version may vary between releases)
 psycopg2:: python-psycopg2

To provide localised messages:

 gettext:: gettext

To update free/busy details periodically, the following software is
recommended:

 Cron::    cron

The management Web interface requires the following packages:

 Apache::  apache2
 Babel::   python-babel

Although not necessarily within the scope of the deployment of this software,
the following mail storage solutions would be used to receive and hold
messages:

 Cyrus::   cyrus-imapd
 Dovecot:: dovecot-imapd dovecot-ldap dovecot-lmtpd

Some test programs and the configuration helper tool need additional programs
provided by other packages:

 envsubst:: gettext-base
