Outlook office 2016 keeps asking for password for my personal email but not for my company email.

I've suffered the same problems for months with Outlook 2013 and just today found this resolution - No more prompts for password.

- Remove cached credentials

1. Close all Microsoft Office Programs
2. Navigate to Control Panel
3. In the search bar, type in “Credential Manager” and select it
4. Select Windows Credentials
5. Under Generic Credentials select the down arrow next to any instance of MicrosoftOffice15_Data:orgid:*your email address* and remove it If you are using Office 365, it may say Office 365 instead of Office15.
6. Open Outlook and input your new credentials when prompted. Make sure you check the box to remember your credentials.

FWIW https://support.microsoft.com/en-gb/office/modern-authentication-methods-now-needed-to-continue-syncing-outlook-email-in-non-microsoft-email-apps-c5d65390-9676-4763-b41f-d7986499a90d

Basic Authentication interim experience

Until September 16th, users signing into Outlook.com through Basic Authentication may experience recurring password prompts in Outlook and other third-party email applications. This is a known issue. After September 16th, users attempting to connect their Microsoft accounts through Basic Authentication will fail to do so.

I'll add myself to the list.

I'm so tired of Word and Excel (the only 2 I use in my personal PC) asking for my credentials everytime I reboot/turn on my PC. And then all I see in this forum is "Go to Credendial Manager, delete all credentials related to..." and blablabla.

I cannot be that difficult to have a piece of software that uses the login you already provided. Come on, it works in every other app coded by anyone.

I have started to trying to get assistance from a different forum. https://www.askwoody.com/forums/topic/outlook-now-cant-find-the-exchange-password/#post-2678425 They know a lot about the misdeeds of Microsoft and they might eventually report this to all of their users as a BIG problem.

No idea how to start a class action lawsuit. I know that Outlook (New) does not have this password issue.

Thunderbird is a good shout, please let us know how it fares :)

I've had some limited success with the following Registry tweaks I stumbled across on Reddit:

HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\AutoDiscover

If exists remove ExcludeExplicitO365EndPoint

HKEY_CURRENT_USER\Software\Microsoft\Exchange

AlwaysUseMSOAuthForAutoDiscover 1

HKCU\SOFTWARE\Microsoft\Office\16.0\Common\Identity

EnableADAL 1

HKCU\SOFTWARE\Microsoft\Office\16.0\Common\Identity

Version 1

Reboot and test.