Thanks, Paul. I did so, using the pop.earthlink.net definition that does actually get incoming mail. (Although, while I tested it, I stopped as soon as I saw it was working, since I don't want to lose any messages until I can be sure things are working both ways.) Anyway, now <sigh> I'm back to that bloody error message 15: <i>Peer connect failure (the host has refused the connection).</i></sigh>
I'm going to try phoning Earthlink, and see if I can get someone who actually knows something about their own product and why it's been so recalcitrant on this new machine. I have to say, all of you at Pegasus are at least trying, and I really appreciate that.
The only two other things I haven't tried yet are on that "Setting for sending mail," on the General tab. One says "Use an alternate e-mail address for the SMPT envelope," with a blank beneath it for said address. The other is "Use this domain name in the HELO/EHLO server greeting," again with a blank for the name. As far as domains go, the only one I can think of that applies in this case is earthlink.net itselft.
As I said, I'll try getting through to their phone support and I'll check back here later.
WriterKate