SBC has recently begun blocking port 25 for sending out email through a 3rd party SMTP outgoing mailserver. This will affect anyone who has set their SMTP server to their domain name. Many other major DSL and cable modem providers such as Earthlink and Cox are also blocking the use of port 25. For these ISP’s, they are requiring their users to use the SMTP server assigned by the ISP.

These measures have been put in place by these ISP’s to try and crack down on spam coming from compromised personal computers, so they can better monitor and control email going through their network. This presents a problem for those individuals wishing to use their domain as the sending server. Users can still keep their email address at their domain if they switch the SMTP server to that of their ISP’s.

LexiConn has made a change to the SMTP servers on our network to help clients continue to use their domain name as the SMTP server. We have made port 26 available for sending out email in addition to the standard port 25, as most ISP’s are not blocking port 26, a rarely used port. In order to try this, you would need to change the outgoing SMTP port setting in your email program from port 25 to port 26, and then you can set the SMTP server to that of your domain.

More detailed instructions can be found in our knowledgebase at:
http://support.lexiconn.com/kb/index.php?ToDo=view&questId=98&catId=12

More details on SBC’s policy can be found in their help docs at:
http://support.sbcglobal.net/article.php?item=4640
SBC also has a form you can fill out to ask that the block be lifted from your account.

- LexiConn Support