Re: Postmaster 'best practices' query

[Jim Duncan <jnduncan () cisco com>]

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