Cannot open outlook.com mail in Firefox

[tcreek]

This began this morning. Receive message - "Your connection is not secure. The owner of col125.mail.live.com has configured their website improperly." Firefox will not allow exception for outlook.com mail.

[DanRaisch]

No such problem here with version 51.0.1 but you seem to be running Firefox 52. Moving this to Firebox Builds.

What security software are you running on that system?

[tcreek]

I am on Firefox 52 and using Windows Defender. I have the same problem on Chrome and Edge but Edge allows an exception. I can only access Outlook.com mail on the Edge browser. This, then, seems to be a Microsoft problem.

[Reflective]

I am on Firefox 52 and using Windows Defender. I have the same problem on Chrome and Edge but Edge allows an exception. I can only access Outlook.com mail on the Edge browser. This, then, seems to be a Microsoft problem.

Not necessarily. I get the same error that you do on that site.

It would appear the security certificate in use is invalid for that particular site. That generates a SSL_ERROR_BAD_CERT_DOMAIN error and could imply that the site has been compromised.

Try one of the alternative URLs for which the certificate is valid such as https://dub111.mail.live.com You'll find more of them by clicking the Advanced button on the col125 site where you saw the error.

[tcreek]

I went to the Microsoft outlook forum and was told to try outlook.live.com to access my email.
That URL, https://outlook.live.com now allows me to access my email.

My old email address for several years was https://col125.mail.live.com. Beginning this morning, that address returned the "Your connection is not secure. . . " message.
It seems that something was changed on the Microsoft end without notifying the users.

[DanRaisch]

It seems that something was changed on the Microsoft end without notifying the users.

Something which seems to occur far too often, based on reports posted on these forums.