Can i use an older version of ubuntu?

my vps provider only has

CentOS 5 (32bit & 64bit)
CentOS 6 (32bit & 64bit)
Debian 5 (32bit & 64bit)
Debian 6 (32bit & 64bit)
Debian 7 (32bit & 64bit)
Ubuntu 12.04 (32bit & 64bit)

so will it work on the older version ? i currently use iredmail but want to check this project out it looks very good.

No, sorry, it won’t work on those.

cheers for the swift reply.