Windows 10 Mail app dumped all four of the outlook.com mailboxes after .NET update 28 Jan 2020

I have four outlook.com mailboxes and two gmail mailboxes registered in the Mail application.  For several years, the Mail app has worked fine with these accounts.

After applying the "January 28, 2020-KB4534132 Cumulative Update for .NET Framework 3.5 and 4.8 for Windows 10 Version 1903 and Windows Server 1903 RTM and Windows 10, version 1909 and Windows Server, version 1909" update, all four of the outlook.com mailboxes have disappeared from Mail, and only the gmail mailboxes remain.  This is grossly unacceptable behavior.  Running the "January 28, 2020—KB4532695 (OS Builds 18362.628 and 18363.628)" update leaves the mailboxes still missing.

When I look in "Settings - Accounts - Email & accounts" all six of the mailboxes are still registered there.

What the hell  happened, and how do we have to recover from this error?

 

Question Info


Last updated February 10, 2020 Views 125 Applies to:

I had this happen to me as well. After some research, this fixed my issue. Go to Settings/Privacy/Email.

Click on the "change" button. My switch was set to off. Switched it to on or accept and the mail returned.

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I had this happen to me as well. After some research, this fixed my issue. Go to Settings/Privacy/Email.

Click on the "change" button. My switch was set to off. Switched it to on or accept and the mail returned.

My App access to Email was already set to On, as were all of the other Email switches, except for Cortana - which I do not use for anything.  The fact that email access for Cortana was turned off _could_ have been a factor, but three different Macs with Windows 10 VMs were set the same way - Cortana access was Off - and Allow Apps was On (one even had People turned off), but no email accounts disappeared from the Mail applications when those Parallels VMs were updated.

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Sorry this didn't help.

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