Outgoing SMTP Servers

Tue Oct 25 19:31:55 UTC 2011

On Tue, 25 Oct 2011 12:55:58 -0400, Owen DeLong <owen at delong.com> wrote:
> Wouldn't the right place for that form of rejection to occur be at the
> mail server in question?

In a perfect world, yes.  When you find a perfect world, send us an invite.

> I reject lots of residential connections...

The real issue here is *KNOWING* who is residential or not.  Only the ISP  
knows for sure; and they rarely tell others.  The various blocklists are  
merely guessing.  Using a rDNS name is an even worse guess.

> However, senders who authenticate legitimately or legitimate sources
> of email (and yes, some spam sources too) connect just fine.

Authenticated sources can be traced and shutoff.  If a random cablemodem  
user has some bot spewing spam, the only way to cut off the spam is to  
either (gee) block outbound port 25, or turn their connection off  
entirely.  As a responsible admin, I'll take the least disruptive path.  
(I'll even preemptively do so.)

--Ricky