ISPs Blocking Port 25 (SMTP)

Many providers are now blocking port 25 (SMTP/Outgoing Mail Gateway) access from their clients to all servers other than the ISPs mail servers.

This means that hosting clients which have ISP service from these providers will not be able to use the SMTP service provided with the hosting accounts (this includes all hosting providers) and must use the mail server of their ISP or change the port 25 to port 587.

Known ISPs who block remote Port 25/SMTP Access

ISP
Outgoing Mail Server
AltaVista Free Access email.1stup.com
AT&T WorldNet mailhost.worldnet.att.net
DCAnet postoffice.dca.net
EarthLink mail.earthlink.net
Microsoft's MSN smtp.email.msn.com
MindSpring smtp.mindspring.com
NetZero smtp.netzero.net
Prodigy Internet smtp.prodigy.net
Sprynet smtp.sprynet.com
Verizon/GTE (Dial-Up) smtp.verizon.net

Back to email setup page