The IP for spymac.com is 213.218.8.109 the 'MX' for spymac.com is mail-in1.spymac.net which has an IP of 213.218.8.221. So when you connect to a mail server at spymac.com and ask it to deliver mail to a spymac.com address it must relay that mail to the mail-in1 server, and it won't do that from just any old IP address. Hence the SMTP error. Try connecting to the other SMTP and see what happens. BTW your SMTP conversation should start with a 'HELO' or 'EHLO'. Paul