I would like to load balance my e-mail servers to multiple machines (3 total clients right now). I already have a load balancer set up that communicates with my 3 Web nodes via the private network, with a public-facing static IP address. Virtualmin is installed on Web node 1, with Postfix, Dovecot, SpamAssassin, and ClamScan. I also have an LDAP server running that Postfix/Dovecot/Virtualmin connects to for user management, this is outside of my 3 Web nodes.
What do I need to do / what considerations need to be made in order to get Postfix, Dovecot, SpamAssassin, and ClamScan working on all three nodes load balancing my e-mail? Each node is configured as an LDAP client, and each also has a mounted GlusterFS volume of /home to share user directories. Is it enough to copy the config folders /etc/dovecot and /etc/postfix? What about SpamAssassin and ClamScan, where are their files stored?