Hello, today a became aware of messages deferred by our MX. I could nail down the issue to "all headers excced 64k bytes". This limit was enforced by OpenDKIM [1] Deferring is questionable. I would prefer reject but that's an other story. The messages in question were sent by an MS365 tenant.
- Do you see such 'huge' message headers, too? - Do you handle/allow larger headerdata? - How much do others accept? To be clear: it's not the size of one header but all message headers submitted so far. Andreas [1] https://manpages.debian.org/bookworm/opendkim/opendkim.conf.5.en.html#MaximumHeaders _______________________________________________ mailop mailing list mailop@mailop.org https://list.mailop.org/listinfo/mailop
