...Full backups may be done with vmkfstools or by means of Rsync and its Delta algorithm (read: https://33hops.com/blog_xsibackup-rsync-considerations.html), to a local datastore or over TCP/IP tunneled through SSH, so any transfer over IP is secure.
SpamSnake/mHost is a open source based spam filtering appliance. Its primary goal is to provide a very flexible platform from which to implement current and future open spam filtering solutions enterprise and small networks.