Confused by this error - I have tried to reply via both Outlook and BT Web Mail and got similar failures - the failed message is my reply to a thread of 3 messages each of which have been previously processed by my Outlook/BT Mail account. The content is innocuous - in fact a single sentence.
Something weird is going on here with BT Mail!
Update : Just tried same thing from BT Mail App on smartphone and it was sent and received OK - curiouser and curiouser
Solved! Go to Solution.
Hi @jethro I'm sorry to see you're getting the 550 error when sending email. We'll be able to ask our email experts to take a look at the server logs to see why this is happening and I'll send you a private message in a moment so you can send over your details to the moderation team.
Tried it out - seems to be OK - just to clarify =, lots of other messages sent around the time of the original message were sent OK.
Thanks for sorting