Hiding hostnames from mail (incoming/outgoing)

[Ewald Jenisch]

I'm about to set up mailing in one of our sub-domains. What I want to
end with is the following:

Mail should be adressed to <user>@<domain>, instead of <user>@<host>.

An example:

User 'joe' works at machine 'ws1.edvz.univie.ac.at'. However this fact
should be hidden from the outside world; i.e. somewone should be able
to address mail to "joe at edvz.univie.ac.at" or even "joe at univie.ac.at".
Naturally mail should finally arrive at 'joe' on his machine
'ws1.edvz.univie.ac.at". When joe replies to the mail it should appear
to the recipient as if it came from "joe at edvz.univie.ac.at" not
"joe at ws1.edvz.univie.ac.at".

I've seen numerous examples of such mail-addresses in the past. Does anybody
out there have an idea how to get that working?

Are modifications necessary in the nameserver (MX-records)? Or should
changes be done to the senmail-config?

Thanks in advance for any help,

Ewald JENISCH                                    NIC-Handle: EJ51
University Computer Center; University of Vienna, Austria
E-Mail: z00ejr01 at awiuni11.bitnet or z00ejr01 at helios.edvz.univie.ac.at
Snail-Mail: Universitaetsstrasse 7; A-1010 Vienna, Austria, Europe