Forum Discussion

Copper Contributor

Apr 07, 2020

Solved

Teams Calendar Button missing - exchange 2010 + Exchange 2016 hybrid on-prem

Hello Tech community, As you can see in the object, I have one Exchange 2010 sp3 RU22 and one Exchange 2016 CU12 (same forest). The 2016 is my hybrid server, all mailboxes are hosted on Exchang...

MSTeams Diagnostics Log 07_04_2020_à_11_40_00.zip86 KB

microsoft teams

Rigs33
Jul 14, 2020
Hello fishizza,

I had a long troubleshoot session with a Microsoft Exchange Escalation Engineer, it appears that the Teams Rest/API protocol is not compatible with mailboxes created in Exchange prior to 2016 CU3.
Finally, we migrated mailboxes directly to Office 365.

Rigs33

Copper Contributor

Apr 29, 2020

fatshark_2k As I mentioned in a previous post, according to this https://docs.microsoft.com/en-us/microsoftteams/exchange-teams-interact, the requirement are:

- sync running

- Oauth configured properly

- At least, Exchange 2016 cu3

But nothing states clearly that the mailboxes have to reside on Exchange 2016 in a multi exchange environnement.

And again, if I move a mailbox from 2010 db to 2016 db, the issue persist..... Whereas if I create a mailbox directly on 2016 db, we have the expected behaviour with Teams calendar.

On your side, did you try to move a mailbox from ex2010 to ex2016, and see if the calendar is showing up in Teams ?

fatshark_2k

Brass Contributor

Apr 30, 2020

Rigs33 , I tested with following. I have Exchange 2010 and Exchange 2016 in 1 organization. CAS namespace points to Exhange 2016 (autodiscover/webmail). Hybrid and Oauth configured on Exchange 2016. When a mailbox is on Exchange 2010 then the user has no calendar app/button in Teams. When i move the same mailbox to Exchange 2016 the user has the calendar app/button in Teams.

Also stated in your article in the matrix is states 'User's mailbox is hosted in' and then for on-prem the requirement is Exchange 2016 Cu3+ so the mailbox has to be hosted in Exchange 2016 cu3+