I am a BT Broadband customer and have a BT email account with 8 email addresses that I have been using successfully for several years. Over the past few days I have been unable to send emails from one of the accounts, emails are received OK. I am able to access the account and send via the BT Webmail page but not when using the Apple Mail system. The account shows as active when checked in the web account and when the connection is checked via the Apple Mail App it also shows it is connected. When sending from the account via Apple Mail I get the following message:
The server response was: We're sorry, but we can't send your email.Either the subject matter, a link, or an attachment potentially containsspam, or phishing or malware.Please check or edit your message and try sending it again. (6-1-1-2) ID (5ED9AFBE09AC22E2)
I have deleted the account from the Apple Mail App and set it up again with the same response. I have also changed the password on the BT Web account and the Apple Mail App without any change.
In case it helps others after changing the password for that account and waiting about half an hour all is now working. Strange as no other changes had been made to that or any of the other email accounts and just that one was affected.