This one has me baffled. I think it might have to do with the AVG
antivirus software I recently installed, with which I am generally
perfectly happy. But it could be something else.

Outlook 2000 is set up to automatically check mail on my ISP's POP3
server every x minutes. It is also set up to pass outgoing message to
the SMTP server as soon as they are completed.

This works fine most of the time. However, occasionally (a couple of
times a week), I will notice I haven't gotten any mail at all for a few
hours, so I manually check mail and get a popup asking me to re-enter
the name of the POP3 server. It "can't find" the server. It's not a DNS
issue. (I get the same thing if I enter the POP server's IP address.)
My Internet connectivity is fine. I can check and retrieve my mail via
a browser-based mail client, or by telnetting into the POP3 server.

Everything else about Outlook works fine in this condition. I can
navigate folders, move messages around, use the Calendar and Contacts,
everything. When I close Outlook, the OUTLOOK process is still running,
as is MAPISP32 (the MAPI spooler). When I kill them manually and open
Outlook again, everything is fine and all of my mail from the past
hours comes pouring in.

Any ideas?