[GRLUG] new Comcast mail blocking?

[Greg Folkert]

On Fri, 2008-12-12 at 12:45 -0500, John-Thomas Richards wrote:
> On Fri, Dec 12, 2008 at 12:29:33PM -0500, Collin Kidder wrote:
> > John-Thomas Richards wrote:
> > > Am I correct in assuming that Comcast is blocking me from connecting to
> > > a specific port elsewhere?
> > >   
> > 
> > Yes, why wouldn't that be the way they'd block things? Their whole point 
> > is to prevent botnets from being able to send spam. You send from a 
> 
> I wasn't thinking about the spam angle; I was thinking only of Comcast
> preventing me from running a server at home.  Good point.
> 
> > random port but you need to connect to port 25 to send mail to an 
> > external network. And so they block you from sending to port 25 so that 
> > nobody can easily spam from your IP or any other IP on their network. If 
> > you control both ends of the link then you can feel free to change the 
> > port # to something (like you did to send the above message.)
> > 
> > Personally, I still don't agree with wholesale port blocking for 
> > everybody but I'm not an administrator at Comcast so I get no say at all.
> 
> I don't have control at the Dreamhost end; they have port 587 available
> for this very reason.  Interestingly, RFC2476 seems to indicate that
> port 25 should be used only when port 587 is "not possible or
> convenient" yet Comcast is not blocking it.

From the looks of it 587 definition has been superseded from RFC2476
(December 1998) to RFC 4409 (April 2006). It defines 587 as a message
submission agent port.

So, they want to make *ANYTHING* not a REAL MTA use this port for
message submission and not for general use by any MTA. In other words,
Thunderbird/Evolution/Lookout/kmail/balsa/mutt/ effectively any MUA
shoudl use 587 for messages it wants delivered.

Personally I am all for it. But if it becomes a standard thing, spammers
will use it as well and it'll be blocked or what have you anyway.

Blah, blah, blah... yeah spam sure is getting old.
-- 
greg at gregfolkert.net
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