ingress SMTP

Mikael Abrahamsson swmike at
Fri Sep 5 03:35:15 CDT 2008

On Fri, 5 Sep 2008, Simon Waters wrote:

> If the ISP blocks port 25, then the ISP is taking responsibility for
> delivering all email sent by a user, and they have to start applying rate
> limits.

MUAs should stop sending email via 25 and use 587 or equivalent instead. 
There is little actual reason why someone should be able to send TCP/25 
SMTP email from a residential connection when most software support 
authenticated TCP/587 submits.

We don't allow most of our residential customer base to speak SMTP TCP/25 
to anywhere at all (and we have millions of them). Wish more ISPs would do 
the same.

Mikael Abrahamsson    email: swmike at

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