Incoming email server refuses authentication even though it has not been changed

Question

Hi. I'm on Windows 10 (and not one step further when stuff like this still happens!) accessing a hotmail.com email account through Thunderbird. I have Eset Password Manager installed. Everything has worked fine for years with the least amount of massaging from me. Until last night!

Overnight my hotmail account will no longer authenticate from Thunderbird. The hotmail server refuses to accept my username or password, I can't tell which. The username is the email address so surely that isn't the problem. The password is accepted to login to the same online. I've even done that and reset the password which seemed to fix things for a half an hour but the problem comes back.

My Thunderbird incoming server settings are: POP; Server: outlook.office365.com; Port: 995; Security: SSL/TLS; Authentication: Normal Password. The login has not changed and is accepted by Outlook online.

Why did this occur out of the blue with no changes made at my end, and what is going wrong here to cause issues like this in the first place? Any advice is appreciated.

Answer 1

Well this gets worse!

I played around with the server settings tying different setups and eventually came around to using the Server "pop-mail.outlook.com" on Port: 995. Suddenly I got access to my account and new emails came in. I thought problem solved. Then, about an hour later it stopped again, same result, same symptoms. I cannot imagine what is going on here.

Is it possible my account has been locked by Micro$oft for some reason? The same login details work when I access my emails through Outlook online.

EDIT: And I've just checked again and Thunderbird reports there are no new emails. It's working. Until I get another batch of those refusal textboxes again. This gets stranger and stranger.