Microsoft may be requesting an app password in the background. Try the steps described here:

(quote)

1. Sign in to your Microsoft account.
2. Under Password and security info, tap or click Edit security info. If you're prompted for a security code here, enter it and tap or click Submit.
3. Under App passwords, tap or click Create a new app password. A new app password is generated and appears on your screen.
4. Switch to the app or device for which you need the password, and enter the app password displayed on the screen.

For more info about signing in to specific devices, see App passwords and two-step verification.

(end quote)

The info may be outdated. What triggers the error may be the page asking you to protect your account by a secondary email or code when logging in using webmail. Try visiting that and enter the email or (let it) send the code.

Also see When you can't sign in to your Microsoft account.

Could you report back?

The information that you furnished is probably OK if the problem is with an app. It's not. The only app that shows up is the one on my smartphone which is working fine. The problem that I am having is being able to use Thunderbird on my laptop. I can sign into Microsoft through the web and with my smartphone, but not through the mail handler (Thunderbird).

Did I miss something in your message?

Did you actually try it? "App" is just typical Microsoft dumbing-down to the lowest common denominator.

OK, I tried to follow your directions. Step 1 is straightforward. Step 2, there is no "Password and Security" info, but I selected the closest tab. Step 3, the only app listed is for my smartphone, and I don't see a place to add an app. If I did, what would I add -- Thunderbird? Step 4, I'm not being prompted to add a pass code, so I don't know where I would add one if I got it in Step 3.

Again, I am able to use Hotmail in all other applications and devices. The problem must be in Thunderbird. I will be traveling for the next couple of weeks and unable to access my laptop to try other solutions. I'll have to get back into this after I get back. Maybe I just need to get rid of Thunderbird and try a new mail handler.

You are not alone (also see this and this question that both came up yesterday, which is no coincidence), but the fact Microsoft is changing things occasionally may be related. The info in the "here" link above was copied from the Microsoft forum and marked as a solution there. Even they can’t provide "the" ultimate answer, and this does not affect Thunderbird only.

Like Zenos said, "app" may not necessarily refer to two-step verification, and perhaps MS may be mixing up user settings for it or just trying to promote (not to say "force") users to set it. If you follow the MS link at the bottom and then "If you recently turned on two-step verification" there, you’ll read "some apps (like the mail apps on some phones) or devices (like an Xbox 360 or Windows Phone) will show an incorrect password error because they can't prompt you to enter a security code when you try to sign in."

I don’t have two-step verification enabled either, yet I get prompted by some security check asking for a secondary contact when using webmail occasionally, which means they need some input, even though the page can be avoided and webmail is still accessible. Also, I never heard of an apparent "Security settings page" until troubleshooting this issue, and that may go for others as well. Both may be causing the error, but I have never experienced them myself, so any user input would be welcome.

One thing is (almost) for sure: Thunderbird does not change nor remove stored passwords by itself, so basically I would not try to change them as a first step. As you said, it is not a password issue.

Instead, it could be a cookie or caching issue, so what you could try is:

• Go to Options > Privacy > Show cookies, and remove all Microsoft cookies.

I don’t think it helps though, as I see no Microsoft cookies (using IMAP), so therefor:

• Go to Options > Advanced > Network & Disk Space > Clear Now...

I’d also be interested in what happens after users accepted and followed any requests when accessing webmail AND/OR the security settings link first, and then logging in again with Thunderbird. Could you or anyone else try and report back?

Another thing is, since I never experienced these login issues, I’m not using any security related software on the machine I access Hotmail/Outlook with. In order to rule that out, one could (or should) try disabling such software entirely.

Please keep in mind that Microsoft can try any method in order to do some "fingerprinting", causing their security check to decide if an app is a bad app, regardless of two-step verification, so anything able to cause changes in (internal) login procedures for instance can cause clients to be blocked. Hence if another app or a mobile device has no issues logging in, there is no guarantee the issue originates from within Thunderbird. Even Windows updates may interfere.

I have exactly the same problem. Soon as I started TB this morning - Login to server imap-mail.outlook.com failed. I can send mail, but not receive it.

Have tried sending Hotmail email from my Andriod mobile - that won't work either...

MS up their usual tricks?

Hi guys, I got a reply from Microsoft support thread. Perhaps this is the problem?

http://downdetector.com/status/outlook/map/

I am in the Cincinnati area, which is in the yellow, so maybe this is my problem. Poopypantz, are you located in the affected area?

Michigan - bright red :(

What puzzles me a bit about the outage map is why I can access hotmail/outlook directly and I can access hotmail thru my Yahoo mail account. But not thru Thunderbird :-\

FWIW, I just removed my hotmail email account from Thunderbird Account Settings. When I attempted to add it again, I get a yellow triangle with "!" followed by these error messages.

This one next to the Password entry box: Username or password invalid

This one just below that: Configuration could not be verified -- is the username or password wrong?

Thank you for the link, it may explain a lot. Very red here, no connection issues though.

poopypantz said

What puzzles me a bit about the outage map is why I can access hotmail/outlook directly and I can access hotmail thru my Yahoo mail account. But not thru Thunderbird :-\

Please keep in mind that webmail interfaces have a different approach, and being able to log in to them does not prove accessing mail servers over POP or IMAP should be working. In the old days when email used to be part of services offered by ISPs, webmail interfaces weren’t even always available for them - nowadays they tend to be the primary way of using email for many people, while they can still be considered as a fallback option. ISP’s and email providers will most probably make sure the web interfaces will work even before fixing "regular" access to their mail servers.

As for the user/password error messages: they can be default for several issues. Again, don’t try to change credentials rightaway if you see one, as that may cause additional issues if proper credentials are lost.

I logged into Hotmail via a browser and set it it to forward all email to one of my other email accounts - seems to be working fine as a temporary workround

Zenos said

Did you actually try it? "App" is just typical Microsoft dumbing-down to the lowest common denominator.

I Actually tried this, and also turning off and then later on 2-step authentication...The app password, and these other steps, DID NOT FIX THE PROBLEM. This all worked fine until 3:am this morning (11/19, east coast time)...no change by me... Outlook com is working fine on my smartphone with android mail app, and gmail, and with my browers on Windows 10...BUT NOT WITH THUNDERBIRD!1!!!

Hello, I found a workaround and posted it there: https://support.mozilla.org/en-US/questions/1147439

(note: very strange way of the Mozilla forum to get you Register = it forces you to ask a question, therefore to create a new thread ... I couldn't find a "Register" button anywhere .. I could just ask a new question, then it allowed me to Register, and my new questions is directly the answer to this post ... sorry .. and blame it on the ergonomy of the site, or on me for not seeing maybe where I could have registered otherwise)

aaFn: Thank you for your info. somehow this is starting to make sense. Looking at the reports, how many people suffer the issue with outlook.com email addresses here? It appears to occur for hotmail ones only, so...

there were many reports last week about service. http://downdetector.com/status/outlook might offer some insight

So experiencing the same issue. I have hotmail forward to my android device and receive mail properly and no issue. I attempt to access through thunderbird on my laptop and get the same repeated error. Reading through the multitude of threads on this site and as another posted noted - the tremendous amount of comm's on the web - there seems to be no answer. What I can gather is Microsoft had communicated a while that there were changes coming to hotmail accounts but nothing to the level of what many are experiencing. Several new sections in security and profiles on the MSN side changed. It seems that Thunderbird has not made any attempts to understand what was coming and its users are having to experience these issues in one off.

Can anyone confirm what the true fix is and if Mozilla or Thunderbird dev team is working on any resolution? Creating an alias as a work around, to me is not a fix - its a workaround. Appreciate any guidance. Because of MSN's poor recognition & policies, I'm looked out of account profile changes because of the Security Key 30 day policy, so I have time.

I had 4 emails queued in Drafts on my Andriod mob since sunday. Just now they've all been sent. And TB seems now to be working without problem with my hotmail account. I didn't change anything, just left it all to wait and see, and now for me at least it seems to be working again.

Yes, looks like Microsoft fixed the thing now, my pure hotmail account works again. If that stays like this for a week, I'll delete the workaround.

Yes it would seem that MS has fixed the issue with their servers. They did note that they are not responsible for 3rd party integration issues - so I am very very interested to hear from Mozilla/Thunderbird Dev what is the resolve go forward. I would expect a better lead time to these types of changes. Not everything is behind a black cloak of secrecy. With as many folks who depend on Thunderbird to this day: MOZ should be better tuned to the ripples that could upset their users.