[dmarc-discuss] Forwarding Calendar Invitations

Sim sim at simonliebold.de
Fri Aug 11 05:31:53 PDT 2017

Hi List,

Person A sends an invite to person B, who forwards it to person C.

If A's domain is on "reject" (or "quarantine"), B's MUA doesn't replace
the original "From:" and C's MTA checks for DMARC, this breaks - well,
works as designed. 

Outlook keeps the original "From" and this explains why sporadically, I
see our domains used by our partner's MTAs.

Do you know of any other MUAs causing this kind of trouble (G-Calendar &
Lightning doesn't)? Any remediation possible? Or just accept to have
smaller meetings?


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