I tried it again this morning and this what I got...
"Sending unsolicited commercial or bulk e-mail to Microsoft's computer network is prohibited."
Remote server has unexpectedly closed the connection (#102).
I am trying to send stuff to 404 people on an artist mailing list that I just took over, but I guess because of the numer of e-mails Microsoft thinks it's spam. Is there any way to get around that or do I have to get a new address to send through?