Rudi Ahlers wrote:
For fail over on the webserver & samba, the heartbeat + rsync works well, but I don't know where to look for the email stuff. I don't need anything fancy, but a shared calendar & address book would be great. It's a 10 user network
email is essentially an on-disk setup, so just setup any software you want ( I recommend roundcube over squirrelmail as a nice web interface - basic, but usable ).
Just put the email storage on the drbd mounted drive and you should be ok.