Yes I can login on the link you sent me, but only one email account is available, not the one that is the issue.
As we are dealing with one problem BTMail email account I was only asking if you can log onto that email account using the link.
Presumably you have used the correct log on username and what ever current password you are now using. What happens when you try to log on?
Do you see the email account when you log onto your MyBT and go to "Your Products" then "Email, Manage".
If you do see it, what section does it show in and what status is it showing?
Do you have it selected as "Favourite"?
Can you access and use the email account from there?
When I logon to my account at MY BT I see the email address and it states it is active. In my emails I can see two accounts and can access them both and I can send and receive emails. I cannot see both email accounts on BT Webmail or Apple devices.
So the email account that is the problem is active only on MY BT
message I get is: Please enter your user name and password correctly please try agin.
I entered the details that the email was restored with BT yesterday.
If I enter my other email details it works fine
Ok, what happens if you click on the 'Forgotten your login details' link on the login page and follow the process by entering the problem email address?
When you try and log onto webmail using the link supplied in this thread are you entering the username and password manually or are you using the browsers "stored" password?
Have you tried a different browser?
When you have been changing the password how have you been doing that?
Have you tried changing the password by accessing your Manage email accounts via your MyBT then clicking on " see options" then selecting "change password" and following the prompts.
So, you updated your Mac which caused the problem to occur but Apple consider it to be a BT server problem that coincidentally occurred at exactly the same time. Strange logic.
Given that the problem occurs on devices that don't use Big Sur but iOS and that other BT mail accounts are working properly on Big Sur and iOS the logic doesn't seem so strange.
I have to agree with licquorice that if the problem only started after you did your update on your Mac that that would be where I suspect the problem lies.
I don't use Apple devices so I am not sure about how linking all your Apple devices with iCloud works but given that your iPhone email also failed after your Mac update that would also point to Apple causing the problem and not BT.
Can you access your BTMail email account using the log on page here?
If you can I would suggest that you delete the email account from you email client/app then restart your device and follow the procedure that I previously gave by setting up the email account manually adding all the settings rather than allowing the app to set it up automatically.
But the other BT mail accounts are working on Big Sur and iOS devices, and a Big Sur update would not directly affect devices running iOS. The linkage between Big Sur and iOS will be the Apple Keychain, that stores log in credentials and is shared via iCloud. A problem here caused by the Big Sur update could propagate via the shared Apple Keychain. But why just this. otherwise vanilla, BT mail account?
It's good one.
My thinking goes along the lines of the update somehow screwed the login details for the account, subsequently all the tinkering about with multiple password changes and account deletions/creations has royally screwed things up.
If we can get a clean start with being able to login to webmail we will have a known good password that we can then move forward with.
I have carried out what you recommended that I have done a number of times, giving the problem email account a new password Guess What it has worked I have the email address on all devices.
I would like to thank all of you on the bt community for your help