The .PST file is simply the file on your pc containing all your emails. It can become corrupted, hence the need to run the repair tool.
Thanks. But how do I repair it?
Fair enough! It may not be. But how do I sort it?
There are 2 possible reasons it suddenly stopped working.
Firstly, you were previously on the BtYahoo mail system and have now been migrated to the new BT mail system and the server details were incorrectly using Yahoo servers previously. Althy incorrect, they would have worked whilst still on the BtYahoo system but not once migrated.
Secondly, Microsoft may have broken your installation with an update
Thanks. Yes, I have learnt about server details and made sure that I was using those set out on the BT website Help. Mail.btinternet.com etc. If Mircroosft have broken the system with an update, how do I rectify that? I am dependent on Microsoft helping me and they just refer me to BT. It just goes round and round!
Having re-read the whole thread, it would seem the problem started when you changed your password.
Not wishing to be patronising, but are you sure it was your email password you changed and not your BTID password.
Thank you for the thought! They are one and the same! And I can access webmail with the new password so I really don't think that is the reason. But, in all honesty what do I know? It's all a minefield and I have no in house Help Desk to help me through it. I am a lonely individual customer who has limited understanding and no help from those to whom I pay a quarterly and annual fee to!!! Once again, thanks for your support
I will ask if the mods can help. Sometimes when passwords are changed, the change doesn't sync across the servers and requires BT intervention. They will post an invitation on this thread.
I don't recognise the term "Microsoft Office Outlook email organiser" . You are using Outlook, with calendar, contacts and lots of other things? Looks likes this on the File page
There are also two versions of MS 365 - one you download the programs to your PC, the other you work on the web. I thought they would be the same but, for example, the one you download cannot transcribe in Word an audio file to text, whereas the online version can. Have you installed your 365 to your PC (which means you can use it offline) or are you working online? If I work on a document or spreadsheet with friends, simultaneously, I have to be in the online version. (I hate doing it). I can't imagine shared working in Outlook.
I'm at the very edge (or beyond) of my knowledge here but if Outlook differs between online and downloaded, that might be worth investigating.