The popular local broadband ISP, Cox, has made recent changes to how it handles electronic mail. These measures were taken to prevent malicious users from exploiting Cox for Spam or e-mail based network attacks.
Technically speaking, they have blocked port 25 (SMTP) except for Cox subscribers sending mail through Cox’s mail server. This will not have an impact for most subscribers. If you have not already followed Cox’s recommendations for outbound mail, you must reconfigure your mail application to use their server.
This will also affect users who use a laptop both with the Cox service and UCInet and have been able to use the same mail configuration in both places, which is no longer possible.
Cox provides detailed information at: http://www.broadbandreports.com/forum/remark,7081800~root=cable,ath~mode=flat