Thanks Stefen, I have a Currys Care Plan & agent tried to sort it out last Friday for me remotely. It seemed to work OK for a day without Ads popping up (am not subscribed to Microsoft 365(?) then back to Ads appearing in Inbox ,delete them & then they might appear in Incoming box (?)rather than deleted.
I cannot now access Windows Mail or previous Outlook. When I try to check inbox it seems to alternate between opening OK & "Access Denied " again.
For some reason I tend to have my Skype open 24/7 & whether it then recognises I have signed in there & the Access Denied then opens OK.
I wonder if my PC is a little "flaky" or Microsoft just playing at Silly B*ggers to persuade me to pay for the 365,which I only use for emailing.
It just seems to be a company operating a form of Professional Ransonware !
Trying the sync only shows my current email address.