[43667] in North American Network Operators' Group
Re: Postmaster 'best practices' query
daemon@ATHENA.MIT.EDU (Jim Duncan)
Mon Oct 22 14:50:41 2001
Message-Id: <200110221849.OAA04195@rooster.cisco.com>
To: wb8foz@nrk.com
Cc: nanog@merit.edu (nanog list)
In-Reply-To: Your message of "Mon, 22 Oct 2001 10:33:56 EDT."
<200110221433.KAA27123@sigma.nrk.com>
Date: Mon, 22 Oct 2001 14:49:34 -0400
From: Jim Duncan <jnduncan@cisco.com>
Errors-To: owner-nanog-outgoing@merit.edu
wb8foz@nrk.com writes:
> A query to help educate me. Feel free to flame away;
> the week is young.
>
> Every site should accept/respond to "postmaster" -- T/F?
>
> Or is it "Every site running mail"....
> Or every box running mail?
>
> IOW: Which of the following are required vice recommended vice
> best practives, etc.
>
> a) postmaster@example.com
> b) postmaster@mail.example.com
> c) postmaster@wizzbang.example.com
> d) postmaster@pop.example.com
> e) postmaster@cisco.example.com
>
> and most important to me: where to I go to justify the
> decisions on same?
The Host Requirements RFC says that if you support "receiver SMTP", you
must support the reserved mailbox "Postmaster".
In my experience, interpreting that statement has been a pre-existing
exercise for the readers for nearly a decade, with many results.
In my humble opinion -- heavily dosed with Jon Postel's Robustness
Principle -- that rule means that if SMTP mail succeeds to _any_ address
for a specific right-hand side, then SMTP mail must also succeed to
"postmaster" at that same right-hand side. So using your examples
above, if I can send SMTP mail to foo@example.com, then I should be able
to send SMTP mail to postmaster@example.com. I would hope that a real
human being would be able to respond, but I realize it's unlikely.
There may be other RFCs that cover this issue.
Jim
==
Jim Duncan, Product Security Incident Manager, Cisco Systems, Inc.
<http://www.cisco.com/warp/public/707/sec_incident_response.shtml>
E-mail: <jnduncan@cisco.com> Phone(Direct/FAX): +1 919 392 6209
