Lockdown...Meh. relative has just messaged me to say their e-mail now appear to other people as
From: XY [mailto:their_name@btinternet.com]
Any idea what webmail setting they have changed or need to change back so it says their name not XY?
They also commented that their bt webmail login link takes them to https://mail.yahoo.com i thought that had ended now...
I suspect that this will not help and they may need BT intervention to resolve this but as a first step can you get them to clear the history and cookies from their browser.
If you or they are not sure how to do that, once you know which browser they are using do an Internet search and you should find the method. It is fairly easy to do on most browsers.