I recently started to have strange malfunctions with my Outlook Express too, but running a full DEFRAG seems to have fixed it. If you haven't run a defrag in over a year, it's probably a good idea. On windows ME it only takes about 2 hours- much improved from the 12 hours+ it took on windows 98. Start - RUN - (type) DEFRAG
WindowsME is a terrible, horrible, no-good, very bad operating system. Upgrade to XP or 2000 and you'll have far fewer headaches.
ive found it a good idea to leave a copy of messages on the server - its an option for pop3. you also specify only leave X days on the server, etc. just some options to play with. i figure just incase my PC gets hosed the ISP server has my backup.
I am uneasy to have my personal stuff lay around in some servers and I don't even know where they are.