[Mailman-Users] mail not being sent/received

Brad Knowles brad at stop.mail-abuse.org
Fri Feb 18 03:28:48 CET 2005

At 8:36 PM -0500 2005-02-17, George Theall wrote:

>  Nope, it's not blocked (I'm on MCI).

	You're looking in the wrong direction.  I was talking about 
inbound connections *to* his address, not outbound connections *from* 
his address.  Many large ISPs tend to block things like port 25 in 
both directions, or do transparent proxying.

	Moreover, I know that many cable modem providers implement 
different policies in different areas, so while one group of Comcast 
customers might not have blocking or transparent proxying that they 
have to worry about, others might.  At the very least, large 
providers like Comcast do not necessarily implement the same policies 
across the board in unison, instead they roll out policy changes, and 
while a certain group of customers may not yet have a given problem 
while others do, given enough time, the policy change will be rolled 
out everywhere.

>  Why don't you send your mail through Comcast's mail servers? You can
>  have Mailman do this by setting DELIVERY_MODULE = 'SMTPDirect' and
>  adjusting SMTPHOST in Mailman/mm_cfg.py.

	Again, we were talking about inbound, not outbound.  But outbound 
is also a legitimate issue, and one that the OP should be concerned 
about.  Again, many providers will block port 25 on outbound 
connections, or transparent proxy them.  In addition, many providers 
place limits on the number of messages you can send in a given amount 
of time, or the total amount of mail volume (in bytes) that can be 
generated in a given amount of time.

	Mailman FAQ entries 
are relevant.

Brad Knowles, <brad at stop.mail-abuse.org>

"Those who would give up essential Liberty, to purchase a little
temporary Safety, deserve neither Liberty nor Safety."

     -- Benjamin Franklin (1706-1790), reply of the Pennsylvania
     Assembly to the Governor, November 11, 1755

   SAGE member since 1995.  See <http://www.sage.org/> for more info.

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