After composing an email and clicking the Send button I get this message:
Sorry your email could not be delivered due to content policy reasons. Please check your message content for URLs, content and subject matter that could be construed as Malware, Spam or Phishing before retrying. (6-1-3-1) [or (6-1-1-1) ] ID (69E784C5056DFCD6)
It happens with both Edge and Chrome browsers, even on very short messages with no links or inclusions.
Any ideas?