Apparently that's the not the only mail server that won't take mail from our new cPanel server. yahoo.com: 2007-03-07 20:42:07 1HP8aJ-00049o-QM SMTP error from remote mail server after initial connection: host d.mx.mail.yahoo.com [184.108.40.206]: 421 Message from (220.127.116.11) temporarily deferred - 4.16.50. Please refer to http://help.yahoo.com/help/us/mail/defer/defer-06.html Yeah, deferred. They never go anywhere. Even on the rare occasion when it connects to a Yahoo mail server the mail doesn't arrive at the sender, either in the inbox or in the spambox of their yahoo account. tombean-isd.org: # telnet 18.104.22.168 25 Trying 22.214.171.124... telnet: connect to address 126.96.36.199: Connection timed out telnet: Unable to connect to remote host: Connection timed out advantex.mail.net # telnet mail.advantexmail.net 25 Trying 188.8.131.52... telnet: connect to address 184.108.40.206: Connection timed out telnet: Unable to connect to remote host: Connection timed out I did manage to get AOL and Google to take mail. The server can ping all of the above. apf isn't blocking traffic to them. The server has reverse DNS. It has a proper SPF record, as do all the domains on it. Any thoughts?