Mail delivery to club users is load balanced across calcium and magneisum. Both run qmail for mail delivery and a kerberos-enabled bincimapd for reading.
Mail is delivered in Maildir format to home directories in AFS, so mail can also be read using any Maildir-capable client (i.e., mutt) from any club shell machine. Delivery to Maildirs with qmail is highly configurable. See dot-qmail(5) for more information.
Ezmlm, also installed on these machines, is nifty mailing list software that is much nicer than majordomo or AMS/Andrew dlists. See ezmlm-make(1) for documentation.
We also offer virtual mail hosting as a service. Contact gripe@club.cc.cmu.edu for more information.