[OFF TOPIC] Re: Pigeonhole Sieve Vacation Reply-To peculiarity with inbound AWS-SES

Stuart Henderson stu at spacehopper.org
Sat Feb 11 08:07:57 UTC 2023

On 2023-02-10, Michael Peddemors <michael at linuxmagic.com> wrote:
> TOP POSTING for clarity
> I think this is getting off topic for the dovecot list.  Vacation 
> messaging is a complex topic, and for the record it does seem that the 
> way they are doing vacation messages could use improvement.
> This should NOT be sent as a BOUNCE <>, and it should NOT come from 
> MAILER-DAEMON, as it is actually from the person with the vacation message.

Pigeonhole is following RFC 3834 which sees it differently, in particular
the RFC tries to avoid anything which might trigger loops.

               Since in most cases it is not appropriate to respond to
   an automatic response, and the responder is not interested in
   delivery status messages, a MAIL FROM address of <> MAY be used for
   this purpose.  A MAIL FROM address which is specifically chosen for
   the purpose of sending automatic responses, and which will not
   automatically respond to any message sent to it, MAY be used instead
   of <>.

> It also should NOT have a precedence header of BULK.

   A response MAY include a Precedence field [I4.RFC2076] in order to
   discourage responses from some kinds of responders which predate this
   specification.  The field-body of the Precedence field MAY consist of
   the text "junk", "list", "bulk", or other text deemed appropriate by
   the responder.  Because the Precedence field is non-standard and its
   interpretation varies widely, the use of Precedence is not
   specifically recommended by this specification, nor does this
   specification recommend any particular value for that field.

>> The actual problem is that Pigeonhole responds to to=<010301863b0211fe-9416f5b2-7e18-4c03-a5e5-2204dd7946f8-000000 at sa-east-1.amazonses.com> instead of to=<rolf at example.de>.

Exactly as it should:

   In general, automatic responses SHOULD be sent to the Return-Path
   field if generated after delivery.  If the response is generated
   prior to delivery, the response SHOULD be sent to the reverse-path
   from the SMTP MAIL FROM command, or (in a non-SMTP system) to the
   envelope return address which serves as the destination for non-
   delivery reports.

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