Alessandro Vesely wrote on 2021-08-19 13:18:
I'd swap SHOULD and MUST between the following sentences:

     If a report generator needs to re-send a report, the system
     SHOULD use the same filename as the original report.

The paragraph is justified by deduplication:

   If a report generator needs to re-send a report, the system SHOULD
   use the same filename as the original report.  This would allow the
   receiver to overwrite the data from the original, or discard second
   instance of the report.

But this works only if the sender ensures to leave the filename unchanged. So it's either a MUST or the paragraph can be omitted altogether.

and

     The RFC5322.Subject field for individual report submissions
     MUST conform to the following ABNF:

For the subject, alternatively, "Report-Id" msg-id could be optional, as it is with the filename.  It is very noisy and doesn't seem to be much useful if it doesn't match the filename, let alone its uniqueness.

The Report-ID is also justified by deduplication:

   The purpose of the Report-ID: portion of the field is to enable the
   Domain Owner to identify and ignore duplicate reports that might be
   sent by a Mail Receiver.

1. So Report-ID is either a MUST to allow deduplication,
2. or Report-ID is not required for deduplication,
(In the filename it's optional, but the filename has a mandatory time range, which the subject has not. Deduplication requires one of these two information. You might use the RFC5322.Date, but this introduces another dependency.)
3. or deduplication via subject is not supposed to be supported.
Is there another use case for a formal ABNF spec of the subject?

Regards,
Matt

_______________________________________________
dmarc mailing list
dmarc@ietf.org
https://www.ietf.org/mailman/listinfo/dmarc

Reply via email to