March 8, 2005
SBC starts blocking Port 25 – without notice?
So for the last 5 years I’ve been using Pobox.com as my email service provider. It’s a great service – if you ignore the fact that you’re paying to have a lifetime email address.
In any case for the last week I was unable to send e-mail from my PC at home and I wasn’t sure why. For a while I thought it might have been transient errors on Pobox.com.
Then last night I finally dug into it, and found out that SBC started blocking SMTP port 25. Without notice.
Thanks SBC.
This is what the folks at Pobox had to say:
We’ve received other comments from SBC users who told us that SBC had suddenly decided to block port 25, so I suspect that you are right.
Because this block is becoming more common, Pobox also runs its SMTP server on another port; your provider blocks external SMTP access by preventing outgoing connections on port 25 (the standard SMTP port), so we run the server on port 587 as well.You will want to locate the settings in your email client where you change the SMTP Server and look for a place to enter a port: enter 587.

