[TriLUG] OT: ATT UVerse internet access

[Matt Pusateri]

On Mar 31, 2011, at 3:35 PM, Chris Merrill wrote:

> On 3/31/2011 2:47 PM, Matt Pusateri wrote:
>> <snip>
>> me(matt at myficticiousdomain.org) from using your server to send my email.  When I send email as
>> matt at myficticiousdomain.org through mail.webperformance.com, I am then relaying mail through your
>> mail server.  This relaying of mail can happen for two primary reasons.  1. Your mail server
>> could be an open relay allowing anyone to send unauthenticated mail through it.  2. I could have
>> an account on your mail server say matt at webperformance and I c ould authenticate to
>> mail.webperformance.com and send mail from my personal domain of matt at myficticiousdomain.org.
>> <snip>
>> Does that make it more clear?
> 
> That confirms that my understanding of "relaying" is correct.  But then I don't see how
> the port 587 helps. The earlier comment was:
> 
> "SMTP-with-authentication-by-default; no relaying. The well-known port is
> 587. See RFC2476."
> 
> If there is no relaying, then I could not use that port to send e-mail to our customers.
> Or am I mis-understanding the "no relaying" part...or taking it out of context?
> 


So if they are blocking outbound port 25 to your mail server, they may not be filtering port 587.  I've never actually seen a home ISP block connections out to port 25.  I can see why some would.  I usually see them blocking inbound so you can't run your own mail server at the house or can't run it on a residential services to force you to upgrade to a business service package.

Matt P.