Thank you, Carl! :) I appreciate the kind offer. It appears I've finally resolved the problem as of this morning, with the help of a second local tech service. I've set up new email accounts, but will continue using the existing ones for a while.

It's hard to know where to start catching up on weeks worth of email. It also seems that some email was deleted from the server a day or so ago -- so if anyone has been expecting a reply from me and hasn't received one, please send the message again.