Against every ounce of good sense that I possess, I switched ISPs to SBC/Yahoo when I moved to Oakland. So far, and because I kind of know what I'm doing, I managed to not let the installation procedure take over my whole computer, but I discovered a few days ago that for some reason, I could not send my booboolina mail using Eudora. I thought it was a problem with knowspam for a while, since sometimes I can't get/send mail because they are having connectivity problems, but this time I could get mail, just couldn't send it. I tried opening a service request, but the (nice but) clueless guy on the other end couldn't figure out what I wanted, and finally wanted to pass me to their hosting services (hosting services? what for?). Google, as usual, came to the rescue:

If you have signed on with SBC/Yahoo and can download email, but can't send email (email not of the yahoo variety), then it's because they have blocked off port 25 and you have to request that they unblock it. The support people won't have a clue what to do for you, so just go to http:\\help.sbcglobal.net/article.php?item=4640. They'll fix you right up.