Messages sent Via Classipress contact form rejected by hotmail/outlook
My users messages sent Via Classipress contact tab on ad pages are rejected by hotmail/outlook. I get the following bounce message from outlook/hotmail:
host mx2.hotmail.com [207.46.8.167]
SMTP error from remote mail server after end of data:
550 5.7.0 (BAY004-MC5F27) Unfortunately, messages from (91.146.108.25) on behalf of (my.com) could not be delivered due to domain owner policy restrictions.
Obviously this is a massive problem that I need to get to the bottom of asap. Normal site notification emails don't seem to be affected.