Check the From header for inbound mail about maddy HOT 2 OPEN

This is exactly one of the checks enforced by DMARC. If sender domain (as specified in From) opts into DMARC, maddy would check if the From domain matches either DKIM signature domain (if one exists) or domain in EHLO. DMARC checking is enabled by default.

While it is definitely possible to implement the check like one you described, I would prefer to not enable it by default to avoid compatibility problems - there are legitimate cases when EHLO will not match From (for example, #603). PRs are welcome. ;)

from maddy.

However, the From header in the body is not match the MAIL FROM command.

This is a clear clue of spam.

I disagree I think this would break tons of staff.

Everything with a bounce handler at the very least, this includes mailing lists, notifications of all kind, and everything that is basically a (legitimate) newsletter or subscription.

from maddy.