Office 365 & Windows 10 Mail app issue

[CraigM]

Hi everyone,

 

I've got a bit of a head scratcher. A few people at my school, myself included, like to use the Windows 10 built in Mail & Calendar app to access our Office 365 accounts when we are at home. Less fuss than full blown Outlook or using webmail - it's good enough to get the job done.

 

However, of late we have been unable to use the app to sign into/add our accounts. Attempting to add an account for the Office 365/Exchange account type results in a long pause, before asking for a password. This is incorrect as after we input out email address, the app should open the Microsoft Modern Authentication window so we can enter our password to connect. This is how I set myself up at home a few weeks back. I also tried going via Settings, Accounts, Email & accounts, which makes no difference.

 

As a test I deleted my account on my home PC and tried setting it up again. Absolutely no luck being able to add the account back again.

 

I can rule out network issues, as this is happening to people on different internet connections at home with different ISP's.

 

I also ran the Exchange Connectivity analyzer to double check everything is hunky dory and I can confirm that everything is good. All DNS records and settings are correct. Full Outlook works as does the Outlook mobile app on our phones.

 

I do see that Microsoft have some Exchange issues listed in the 365 admin panel, but I'm not sure if these could be causing the issue. it's really hard to say.

[chaplic]

What does azure ad connect sign-in log say? anything interesting? have you put a block on activesync devices in Exchange?

[CraigM]

What does azure ad connect sign-in log say? anything interesting? have you put a block on activesync devices in Exchange?

 

Long story short, a combination of resetting and uninstalling+reinstalling the app made it work again. I've been pushed for time this week, but my suspicion is that it's a combo of the latest app version and last Windows 10 2004 cumulative update. Very quick and dirty testing showed that a fresh unpatched 2004 install wasn't having the same issues adding the account.

 

I will try looking at it properly this weekend and see if I can figure out what the trigger for failure actually is.