IMAP | OAUTH2.0 | Thunderbird Email Configuration |

Copper Contributor

Hello Team,

I have 2 separate standalone forests without INTERNET, in which Exchange Server 2016 CU22 , & Exchange Server 2019 CU11 is running independently on On-Premise servers. This question is not about 2 forests or their configuration. The users are separate and I don't need anything between them.


1. I was recently asked to configure Thunderbird Email Client (latest one) and it was not working. Emails were receiving but unable to send emails. It keeps giving message to either login or certificate warning.


2. I started testing and re-configuring IMAP Services. Now IMAP Profiles are successfully configured in Outlook Client but not on Thunderbird. Test-IMAPConnectivity works fine.


3. Also, thunderbird client is not able to auto-configure or search for the configuration. Autodiscover Service is configured correctly.


4. I noticed that, I have configured Set-ClientAccessService -AutoDiscoverServiceInternalUri correctly whereas I have left Set-AutoDiscoverVirtualDirectory -InternalURL to Null. Is this Correct? I searched for many articles for virtual directory configuration but they don't configure AutoDiscoverVirtualDirectory Am I missing something here.


5. Is there any SMTP Auth that I need to configure?


6. I was reading about OAUTH2.0. Do I need to configure anything in this regard? I'm not planning on upgrading the infrastructure for next couple of months as it is not needed urgently by business.


5. Is there a way or offline tool to test for Exchange Certificates, TLSCert etc? I reconfigured Microsoft Exchange Server Auth Cert because it was not appearing in Get-AuthConfig...


There is a strong reason why it has no internet, so please don't ask me to upload logs. Please share the commands and scripts, I will proceed from there.


LATEST UPDATE: I came across this URL

and understood that I might I have to enable SMTP Auth at Organizational or Mailbox Level. The sad part is I was not able to find the settings in both servers. I don't get any option listed as "SmtpClientAuthenticaionDisabled". Is this command not available in my version of exchange.



Thanks in advance



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