ISP port blocking practice

Dan White dwhite at olp.net
Fri Oct 23 22:15:45 UTC 2009


On 23/10/09 17:58 -0400, James R. Cutler wrote:
> Blocking the well known port 25 does not block sending of mail. Or the
> message content.

It does block incoming SMTP traffic on that well known port.

> I think the relevant neutrality principle is that traffic is not blocked
> by content.

My personal definition doesn't quite gel with that. You're deciding for the
customer how they can use their connection, before you have any evidence of
nefarious activity.

Would you consider restricting a customer's outgoing port 25 traffic to a
specific mail server a step over the net neutrality line?

-- 
Dan White




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