[Mimedefang] Verizon and greylisting

Joseph Brennan brennan at columbia.edu
Sun Dec 24 12:54:09 EST 2006

--On Saturday, December 23, 2006 10:13 AM -0500 Jeff Rife 
<mimedefang at nabs.net> wrote:

> So, it's very possible that your list has more than one owner, but no
> external MTA should be sending a DSN to multiple recipients...the
> single recipient would be something like "list-owner at yourdomain.tld".

Mailing list software fiddles with things because it is desirable to
send DSNs to the list owners instead of to the writer of the message.
The message comes into the list host with the writer of the message
as MAIL FROM.  The bounce goes out of the list host as MAIL FROM:<> and
RCPT TO the several list owners.

David makes a good point though about smaller systems.  You might
happen to know that no two people on your system are co-list-owners.
That kind of knowledge lets you rule out some otherwise possible cases.

Merry Christmas Eve!  I wonder what attacks we will see this night.

Joe Brennan

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