Charter blocking Port 25

Thu Jun 10 15:26:35 UTC 2004

On Thu, 2004-06-10 at 16:28, Todd Vierling wrote:
> On Wed, 9 Jun 2004, matthew zeier wrote:
> 
> : But this is different - I'm not running a mail server -on- my Cox
> : connection.  I'm running one external to Cox but I can't connect to
> : port 25 on it.
> 
> That's why port 587 was invented.  It's the MSA (mail *submission* agent)
> port, intended only for initial injection of mail into the SMTP delivery
> network.  Learn it, believe it, use it.  8-)

Mail *SPAM* Agent? ;) when spammers also start probing for that port...
A site that has a bad port 25 policy also will likely also have a bad
MSA policy. MSA's can also be open relays just like standard port 25.

Splitting submission from transfer seems like a good idea though, but
in the light of good MTA's, so that the MSA don't need to add a handfull
of headers and also SMTP-AUTH and TLS it doesn't make much difference.

Requiring *Authentication*, may that be on 25 or 587, is the way to go
here... but then still that 'neighbor' will have a misconfig and spam
straight away. Not even talking about the bots.

Greets,
 Jeroen

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