By MAS MVE Exchange Server, Windows Server, Active Directory, Virtu alization, Skype for Business, Microsoft Teams Expert.

Sometime when we run Outlook connectivity from
https://testconnectivity.microsoft.com/ (ExRCA) we get an error like below

If you are running Exchange 2013 SP1 or Exchange 2016 you can easily fix this error by doing the below steps.

Open Exchange Admin Center (EAC) and navigate to Servers–>Virtual Directories and filter by server and Mapi as in the below screenshot.

 

Now Select the Mapi vrtual directory and click the pencil button.

 

Ensure you ticked Windows Authentication -Ntlm, Windows Authentication – Negotiate and Server to Server authentication (OAuth).

Below is the command to check authentication methods on MAPI virtual directories.

Get-MapiVirtualDirectory | fl identity,iisauthenticationmethods

Set the authentication using the below command

Set-MapiVirtualDirectory -Identity "EX2013\mapi (Default Web Site)" -IISAuthenticationMethods Ntlm,OAuth,Negotiate

 

Ran the test again