Comcast blocking port 25? (not what you think)

[bscott at ntisys.com]

On Mon, 10 May 2004, at 6:47am, travis at scootz.net wrote:
> Recently my parents (that use Comcast) can no longer connect to port 25 of
> my server.. one that is legit, has correct reverse and MX records.
> 
> Has anybody else seen this?

  More and more ISPs are blocking port 25 outbound on consumer feeds to
fight spam.  I'm pretty sure that's what you're seeing.

  You have two options: (1) Configure their system to relay through
Comcast's SMTP relay when on Comcast's network, or (2) use an alternate
means of submission.

  An "alternate means of submission" might mean adding an additional SMTP
listener on a non-standard port; using an MSA (Mail Submission Agent); using
a tunnel of some kind (such as with SSH or IPsec).

-- 
Ben Scott <bscott at ntisys.com>
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