Hi there rgooding54
if you are having problems with your @btinternet.com email address, these are home/residential email addresses. If you go to their chat, or call 0808 100 6778 they will be able to help you get yor account working again.
Mailbird might be able to detect server settings for Btinternet.com automatically for you.
Step 1: Click on the File tab in the upper-left corner of the Outlook window.
Step 3: Enter your new email address and click Connect.
Step 4: On the next screen, select IMAP.
mail.btinternet.com. 993. SSL. mail.btinternet.com. 587. TLS.