🚀 go-pugleaf

I'm in need of some references on the topic of Unix/Mac/PC email
gateways.

These systems exist in various "forms" on our lan:  

Independent PCs, Macs, and Workstations are used as "terminals" to
other larger departmental systems.  In some cases the systems are not a
member of that department but arrangement is made so users can
communicate via email (the policy is system by system).

Another lifeform is the WordPerfect Office Lans.  These folks
communicate fine amongst themselves, but there is no "definitave
gateway" in place for them to be able to communicate from WPO mail
to say, the Library which uses Unix/ucb/elm/pine, and vice versa.

Same goes for Macs.

There is not central administration on the LAN here.  There is the
possibility that some system/resources can be set aside for this task.

We would like to be able to afford all campus users the ability to
inter communicate (as well as to internet).

Can anoyone offer any hints?  This would seem to be a common problem of
even small institutions like our own, and probably addressed in several
different ways.  Any expreiences, references or pointers are very much
appreciated.

Thank you,
-johnj