Duplicate reports are now discarded

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.