[MM3-users] Re: Office365 posts shunted (authres.core.SyntaxError)

Hi Steve --

Thanks for the response. You are correct in the fact that I've enabled/configured the ARC module, however, I don't think Mailman is adding that (malformed) header considering I'm now HOLDing the test email(s) sent to our postfix inbound MX servers *before* they are LMTP'd to the Mailman server and its already there when I postcat it.

At the same time I also can't fathom that Office365 has this wrong (still?) and no one has noticed/complained?