Outlook 2016 doesn't accept password or app password

So my version of Outlook that I installed will no longer support Basic Authentication? How do I know if it is an Outlook 2016 MSI version?

From: Modern Authentication Methods now needed to continue syncing Outlook Email in non-Microsoft email apps

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

If you use Outlook for Windows: 

Outlook supports Modern Authentication in all current Microsoft 365 subscription SKUs and Outlook 2021 LTSC (any SKU with build 11601.10000 or higher) when connecting directly as Outlook.com. If your Outlook is configured to connect to Outlook.com using POP or IMAP, Modern Authentication is not supported. This means that when Basic Authentication is fully deprecated, it will no longer connect.  For this scenario, you have a few options:

Option 1: Get a newer Outlook email app which supports Modern Authentication

If your Outlook client does not support Modern Authentication, you will need to upgrade to the latest version and then setup using Outlook.com Sync. You can either purchase a new Outlook License, use the Outlook that is included in your Microsoft 365 subscription, or download Outlook for Windows for free.  

Option 2: Switch to Outlook.com/Exchange Syncing

Instead of using POP/IMAP and SMTP, create a new Outlook Desktop profile and then add your Outlook.com account using automatic account configuration, which will add the account with Modern Authentication. To do this, please use the following guidance:

1. Create a new Outlook Desktop profile. For more information, please go to Create an Outlook profile.
2. Add your Outlook.com account. For more information, please go to Add an email account to Outlook.

The following versions of Outlook Desktop do not support Modern Authentication for Outlook.com:  Outlook 2007, Outlook 2010, Outlook 2013, Outlook 2016 MSI, Outlook 2019 LTSC. Any release of Outlook Desktop with a version less than 11601.10000 does not support Modern Authentication for Outlook.com.

Outlook apps are available for free and can be downloaded directly from the Microsoft Store on Windows, the Mac App Store, iOS App Store, or the Google Play Store.  

After your download the new email app, add your accounts and they will all be configured to use Modern Authentication and sync properly, helping keep them safe.

So my version of Outlook that I installed will no longer support Basic Authentication? How do I know if it is an Outlook 2016 MSI version?

HI.

Hi all,

I am using a Hotmail account with Outlook (desktop) Professional Plus 2016, with version (16.0.5450.1000) MSO (16.0.5452.1000).

Is my Outlook version the reason why I am getting the repeated password prompts? Or, is my application version okay for OAuth (in which case, I believe it should just be a matter of removing and then re-adding this email account to Outlook)?

TIA!

The one seemingly silver lining to this cloud is that spam to the affected accounts has diminished dramatically.

Can you add a comment to your Google ticket with link this thread here? Google is sometimes slow to respond but they are generally much better than Microsoft. This is a serious issue and would trigger losing of some Gmail users.

For me, I moved my Hotmail items to Gmail and I am about 90% done. Moving of calendar from Hotmail to Gmail did have a good benefit that while I am giving up a bit on privacy, I did get better use of Google Assistant/Home with more useful reminders.

With the upcoming crazy changes to Windows 11, I am going to move my computing needs from Windows as well.