How to disable spoofing warnings in Office 365
(Thanks to 
Mail-List.com Email Discussion Groups)
Microsoft / Office365 / Outlook / Live / Hotmail will sometimes put warning messages on emails from your mailing list.
This sender failed our fraud detection checks and may not be who they appear to be. Learn about spoofing
This message is placed at the top of the email.
It does not block the email, but it confuses the receipent.
