We have had a couple of recent threads on duplicate DMARC reports,
especialy those from one large email outfit in particular.
A little web searching brought up this page from DMARCwise:
https://dmarcwise.io/changelog/2025-08-01-reports-deduplication
Starting 1 August 2025, duplicate DMARC and TLSRPT reports are
automatically detected and discarded.
Some email service providers like Google are in fact known to
sometimes deliver several copies of the same report, leading to
incorrect statistics.
A report is now detected as duplicate if an identical report was
received from the same sender in the previous 24 hours.
Although the DMARC specification suggests the use of the Report-ID for
deduplication, some email providers tend to reuse the same IDs over
short periods of time, therefore we’ve opted for a stricter algorithm.
That last paragraph isn't very clear. Are they saying that some
providers use the same Report-ID for *different* reports ?
--
Andrew C. Aitchison Kendal, UK
and...@aitchison.me.uk_______________________________________________
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