On Mon 01/Feb/2021 17:29:23 +0100 John R Levine wrote:
3.3. Transport
Email streams carrying DMARC failure reports MUST conform to the
DMARC mechanism, thereby resulting in an aligned "pass". Special
care must be taken of authentication, as failure to authenticate
failure reports may result in mail loops.
Reporters SHOULD rate limit the number of failure reports sent to any
recipient to avoid overloading recipient systems.
Not MUST?
You might have other ways to prevent mailbombing, e.g., only sending failure
reports to people who you know have bigger mail systems than you do.
Right. However, Murray recalled Section 6.3 of SMTP:
Whatever mechanisms are used, servers MUST
contain provisions for detecting and stopping trivial loops.
Mailbombing in general is not a loop. Two report generators reporting each
other's failure to authenticate a failure report /is/ a loop. So it deserves a
MUST. Perhaps:
Reporters SHOULD rate limit the number of failure reports sent to any
recipient to avoid overloading recipient systems. In addition,
reporters MUST ensure that such rate limiting or any other means
can effectively stop possible mail loops.
?
Best
Ale
--
_______________________________________________
dmarc mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/dmarc
