Outlook not syncing with Gmail

Microsoft has ended basic authentication methods. This is to help secure their apps from attackers who can access credentials and use them to access resources. 

This means that signing into Google using third party apps requiring legacy authentication will not work going forward. 

reference: https://community.spiceworks.com/topic/2475449-outlook-no-longer-working-with-gmail

There is a workaround for this issue while Google is working on how to implement the new authentication method. 

Here are the steps in order to configure access for third party application using the Google Admin console: admin.google.com 

1.) Log in to the Google Admin console (this is assuming you have admin access) 

2.) Navigate to the side panel and go to "Security"

3.) On the Security tab go to "Access and data control" and under that go to "API controls"

4.) From there, you go to App access control and click on "Manage Third-Party App Access"

5.) You will see a list of configured apps and you go to the list of accessed apps from third-party apps (click on "View list")

6.) Once you find the application, you can click on "Change access" in order to configure the third-party app to have access to Gmail.

7.) In order to fine tune the search, go to "Add a filter" and select Requested services, check Gmail, and hit Apply

8.) Once the filter is set, you can click on Change access for Microsoft apps and services

9.) Keep the scope as Grubbrr (all users) and hit Next

10.) Click on "Trusted" and check the box that says "Allowlist for exemption..."

11.) Hit Next and move on to Review and then hit Accept

12.) Now you should see Microsoft apps & services as Verified and Configured

Here is a screenshot for reference: