I only just noticed this thread...
Our central mail hub "ppsw" is of a similar scale to the other academic
sites that have already described their setup. We have somewhat over
30,000 users -- about 32,000 on the central message store, but there are
additional users on departmental systems who also receive email via ppsw.
We deal with about 10GB or 300,000 messages per day (not counting the
hundreds of thousands that are rejected at SMTP time). We have over 150
virtual domains and we relay to over 60 departmental servers. We also have
over 3000 mailing lists.
Email is delivered from ppsw to the Hermes message store (running Cyrus)
over LMTP. Outgoing Hermes email uses stub Exim configurations on the
client-side machines (webmail etc.), and we'll soon be supporting TLS+AUTH
for message submission from workstation MUAs.
The Central Unix Service does more conventional local delivery for its
users (similar to what Hermes did before Cyrus), albeit over NFS.
--
Tony Finch <fanf2@???> http://www.cus.cam.ac.uk/~fanf2/
Mail Support, University of Cambridge Computing Service
New Museums Site, Pembroke Street, Cambridge, CB2 3QH
