while testing new security GPOs, i've found the problem that with E-Mails that contain HTML and Plaintext, Outlook always complains about invalid signatures or tempered messages, even though with the same E-Mails as pure HTML or pure Plaintext, Outlook has no problem with the signature. Can i fix this, or is this a Outlook bug?
This doesn't seem to be a problem with forced conversion, and i cant force use of HTML or Plaintext.