Modify your /etc/apt/sources.list:

• Add “contrib” and “non-free”

you should have something like this:

deb http://ftp.fr.debian.org/debian/ lenny main contrib non-free 
deb-src http://ftp.fr.debian.org/debian/ lenny main contrib non-free 

deb http://security.debian.org lenny/updates main contrib non-free
deb-src http://security.debian.org/ lenny/updates main contrib non-free

deb http://volatile.debian.org/debian-volatile lenny/volatile main contrib non-free
deb-src http://volatile.debian.org/debian-volatile lenny/volatile main contrib non-free

• Add an OBM repository (see below).

Add one of these repositories to your sources.list to install OBM on debian Lenny or Etch.

# Stable repository with current version 2.4.0:
deb http://deb.obm.org/24/stable obm obm

# Latest releases (alpha, beta, rc or stable):
deb http://deb.obm.org/24/latest obm obm

# Nighty build (use with care):
deb http://deb.obm.org/24/nightly obm obm

# Oncommit build (can be broken at any time):
deb http://deb.obm.org/24/oncommit obm obm

Named repositories for old versions :

# Only stable versions here
deb http://deb.obm.org/23 obm obm
deb http://deb.obm.org/22 obm obm
deb http://deb.obm.org/21 obm obm

Be carefull, those packages are built to run on dedicated obm servers.

Nightly and Oncommit packages require manual install/update database from scripts (”/usr/share/obm/www/scripts/…”)

For sun-java6-jdk you need to have contrib and non-free.

Just add the chosen repository to your /etc/apt/source.list :

deb http://deb.obm.org[VERSION] obm obm

and

wget -q  http://deb.obm.org/obmgpg.pub -O - | apt-key  add -
aptitude update
aptitude install obm

Alternatively, if you want opush and all OBM features on a single server, you can use the “obm-full” package:

wget -q  http://deb.obm.org/obmgpg.pub -O - | apt-key  add -
aptitude update
aptitude install obm-full

OBM use sun-java6-jdk package, so you must use debian etch backports, moreover if you want install 2.2.x, postgresql 8.3 (backports) is the default SGBD. We recommend also to use debian volatile if you want more recent clamav and spamassasin packages.

add to your /etc/apt/sources.list

deb http://deb.obm.org/[VERSION] obm obm
deb http://deb.obm.org/jetty obm obm
deb http://www.backports.org/debian etch-backports main contrib non-free
deb http://volatile.debian.org/debian-volatile etch/volatile main contrib non-free

and

wget -q  http://deb.obm.org/obmgpg.pub -O - | apt-key  add -
aptitude update
aptitude install obm
aptitude install obm-funambol