Like many others here I am being plagued by the Error 553 problem which doesnt let me send a high proportion of my emails.
Is there a solution that doesnt involve hours on the phone to BT?
I have moved your post onto your original thread. Posting the same problem on more than one thread causes duplication of effort and confusion.
I have notified the moderators of the forum about your problem. Once they have read this they may be able to help. They are very busy at present so it can take up to 48 hours for them to contact you. They will do this by posting on this thread.