Outlook 2016 Constantly Asking For Credentials

Description

This article will cover a few fixes for anyone using Outlook 2016 on Windows who is constantly being asked to enter their password.

Requirements

  • Outlook 2016
  • Windows 7 and above

The Process

Please try the below 3 fixes to resolve the issue:

Option 1 - Manually Update/Add mailbox credentials to Credential Manager & rebuild Autodiscover.xml file

  • Go into Control Panel > Credential Manager > Windows Credentials > Remove/delete any records with the users mailbox address
  • Download the SaveCredentials.exe tool from here
  • Run the SaveCredentials.exe as administrator
  • Enter the mailbox username and password
  • Next navigate to %LocalAppData%\Microsoft\Outlook\
  • Locate the file that ends in Autodiscover.xml
    • Note: File may look something like this: f0a4256167a8597a89das6hf01c6bb1b - Autodiscover.xml
  • Delete or rename this file
  • Open Outlook 

Option 2 - Revert to an earlier version of Office 2016

Go to the following Microsoft article and follow the steps from here
 
Option 3 - Edit registry to ExcludeExplicitO365Endpoint (do at own risk) 

  • Open regedit
  • (Highly Recommended) Create backup. See this Microsoft article
  • Navigate to HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\AutoDiscover
  • Add new DWORD, give it a name of ExcludeExplicitO365Endpoint and value of 1
  • Restart computer
  • Open Outlook, may be prompted once to enter the users credentials