Imap server questions

[Michael Heldebrant <hmike@portalofevil.com>]

	I'm asking here (not debian-user) because I'm looking to set up a imap
server behind my firewall which will be port forwarded from the firewall
to an internal internet unrouteable ip address.  I'd like to know:

Which is the most secure way:

1.  to authenticate myself to my server

2.  to transfer the mail from the server

and which software packages should I focus on installing for the actual
server and ssl layers ... etc ...

I'm also curious i I only need to forward the imap and imap-ssl ports or
if there are anymore that I need to worry about.  I'm fairly new to imap
but not to linux so I'm not going to need a whole howto.  Just a few
pointers.

--mike