The correct settings for BTMail are as per the following link.
BT Email server settings | BT Help
Can you answer the question I asked whether or not you can access and use your BTMail account using a web browser when using 4g?
I can confirm I can use BTMail using the web browser whilst on 4G - it’s only the third party iPhone Mail app I can’t.
I still suspect that your email account is a Basic account.
As I said it should be showing in your MyBT and as it is not there is a problem somewhere.
Was your email account set up from a BT Broadband account that you were the account holder ie it was in your name on the bill or was it set up on a BT Broadband account which you were not the account holder.
Have you tried uninstalling the email app on your iPhone and have you tried a different email app such as the BTMail app.
The BT app does work on 4G but I’m trying to understand why Apple mail app doesn’t.
I wish you had said that earlier!
Have you tried uninstalling it and then reinstalling it.
My email address is a sub email. My husband has the primary one set up years ago along with mine
All the things I mentioned earlier are now irrelevant because of the extra bit of information you have now supplied about the BTMail working and it only being the Apple app that does not work.
The problem would appear to be with the Apple app and nothing to do with your BTMail account.
Yes -I tried uninstalling and installing and just the same problem.
The BT agent suggested I go to an Apple Store and ask them so maybe that would be best.
Ok thank you 👍