Yesterday our BT email was working perfectly. This morning when we try to reply to an existing message, or when we compose a new message, the following error message is displayed when we click Send: 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) ID (5ED9BDD009711AA2) [Err code: 553]
The last message I tried to send definitely had no URLs - the subject matter was "Test of email system" - and the message was "Seem to be having some problems so am just testing to see if this message can be sent. If you do get it, just ignore it. M" Seems pretty innocuous to me.