ISP's and service providers who block outbound smtp port 25 (OP25B)

EQ Admin

EQ Forum Admin
Staff member

The following is a list of service providers who block outbound email traffic on port 25.

If you have any additions to the list please reply. :thanks:

  • AOL
  • AT&T
  • Belgacom
  • BellSympati
  • Charter
  • Comcast
  • Coqwest
  • Earthlink
  • Flashnet
  • Free (Blocking can be disabled on user's request)
  • Frontier Residential
  • Hotmail
  • JEAG (Japan ISP's, around 50+ block port 25)
  • Mindspring
  • MSN
  • MediaOne
  • Netzero
  • Orange (Wanadoo / France Télécom, Blocking can't be disabled unless the user pays for a static IP address).
  • Verizon
  • Yahoo

Big Dan

EQ Forum Moderator
Frontier (DSL) does -- in my area -- I notice some ISPs do it on a geographic for some reason.

In talking to Frontier tech support back when I had them I was told if I upgrade to a business account the block is no longer active.

Big Dan

EQ Forum Moderator
Whew this thread just saved my tail. I setup a buddy of mine's domain on my server and was having him setup his Comcast address but it wouldn't work. Nice to know that they block port 25, I'll have to work around it. ;)