[Discuss] DMARC issue, Yahoo and beyond

[Richard Pieri]

Bill Horne wrote:
> /will/ /not/ /see/ my post, because *their* email server will reject my
> email, since the Mailman robot modifies the "Subject" line and does
> other things that break DMARC. Someone correct me if I've got that wrong

Rewriting fields created by originator or sender when this isn't
absolutely necessary to ensure validity arguably breaks RFC 2822.

On the other hand, the Subject field is optional and the contents aren't
guaranteed to be constant by RFC 2822 so DMARC's dependence on such
constancy also arguably breaks RFC 2822.

Either way, if removing the Subject field rewrite solves the problem
then do it. The alternative is munging other headers in ways that
blatantly break RFC 2822. Less munging is always the technically
superior choice.

-- 
Rich P.