Microsoft Exchange account in Mail "Unable to verify account"

I had that same problem with my Exchange accounts and found it to be caused by time and time zone settings that did not match my location. Here are the settings I recommend: Date & Time: Set time and date automatically, and also Set time zone automatically using your current location. In the Mac Calendar, Turn on time zone support. Exchange is particularly sensitive to time and time zone settings, whereas some other providers are not. If the Turn on time zone support toggle stops working, I had luck resetting things in Monterey by deleting Calendaragent in Activity monitor. I've read that in Ventura, exchangesyncd replaces Calendaragent.

When I try o add my outlook account it’s unable to verify account information

Using app passwords with apps that don't support two-step verification (microsoft.com)

What about application passwords? Will that keep working?

If application passwords are being used for MFA (Multi Factor Authentication) along with basic auth as another auth mechanism, then when basic authentication is disabled, app passwords used for MFA will stop working too.

Where can I find more information?

There are several resources that we wanted to provide here as additional reading:

• Basic Authentication Deprecation in Exchange Online – September 2022 Update – this is a comprehensive post containing more information about this effort.
• Deprecation of Basic authentication in Exchange Online – our official documentation related to this effort, with links to much more information and guidance.

https://techcommunity.microsoft.com/t5/exchange-team-blog/exchange-online-email-applications-stopped-signing-in-or-keep/ba-p/3641943

Exchange Online email applications stopped signing in, or keep asking for passwords? Start here. - Microsoft Community Hub

This information was helpful to understand why the Mail app suddenly stopped working on my old iPhone 6 - it's simply too old to support the new way Microsoft wants to do authentication.

For the record, I even tried downloading the Outlook app on the iPhone 6, but it downloaded an old version which also refused to connect. ¯\_(ツ)_/¯

Microsoft has been known to link many of their accounts now to the iPhone/Android app called Authenticator. Depending on the use of the account, if it is a school or private company they may require multifactor authentication with the phone registering a code to login the account.

If it is a personal hotmail account, I would get your settings directly from their website logging in http://www.outlook.com/

Are you saying this doesn't work?

Go through setting everything up to a Fake Server, none of the Apple choices, replace the part after the @ sign with like @fakeserver.net when setting up this fake account, use all the right ports authentication, & passwords, wait for mail to say it failed do you want to save this account anyway, say yes, then you can go back in & edit the 2 servers to Earthlink.com or whatever instead of @fakeserver.net

Mac's Mail App is not as modern as iOS's Mail app, Many eMail providers now require a separate App Password different from your eMail password…

Then you may need Ways to securely access AOL Mail…

https://help.aol.com/articles/allow-apps-that-use-less-secure-sign-in