Check
. rkhunter
. rootcheck (cron)
. Prevent DOS and flood.
qmail
. Emails can just be send from within server to any dmain or from DOMAIN vía STMP; absolutely no relay from SMTP.
. patches for qmail.
Ports
. Close all unnecary ports.
Info about how move qmail email folders and sync mysql until dns propagation (what happens if propagation is done and mysql is in slave?)
Info about how move qmail email folders from other server.
Info about how to sync mysql until with old server until dns propagation is finished.
And a few other things.
