While we're almost off topic:

Some ISPs (e.g. Argo) alias a subdomain to a single mailbox. e.g.

foo@bar.isp.co.uk goes to one mailbox bar@isp.co.uk with the From: fields
intact. You can then use the From: fields rather than the envelope to sort
the mails to different users. Can anyone recommend a good program to cope
with this? 

Stephen Borrill