AT&T Internet CustomersClick Here for help with AT&T Internet and Email Services: AT&T Residential customersAT&T blocks port 25 for its residential customers using the following mail servers and you must send mail out through AT&T's servers. (ameritech.net / att.net / bellsouth.net / flash.net / nvbell.net / packbell.net / prodigy.net / sbcglobal.net / snet.net / swbell.net / wans.net / wans.net / worldnet.att.net). AT&T Business CustomersBusiness customers do not have any ports blocked on their service. AT&T recomends your outgoing server be set to host.isp.att.net / using Port 465 Contact AT&T Tech Support directly: |