Issue - Microsoft Teams external chat [English/German]

[Danijel_dicom]

Dear Community,

following problem. I'm not able to contact/chat with external Sfb and Teams Users.

I have allowed external communication in the admin center.

We are in "Teams only".

I can not search for external Users in Microsoft Teams. 

(i have found a workaround, how external Team can contact me - they call me - it rings on my side - and while it is ringig, the other side starts a chat. Then its working. If they try to contact me without this workaround, a chat is started saying "sfb external" -  we are not using sfb anymore - and gets an error that the message could not be sent)

History:
We had an on premise Sfb Server running, which is unactive since 2017. 
This week i have deleted all internal DNS entrys mentioning skype, lync etc.

Our external DNS was updated to:

We only want to use Teams. Exchange is still on premise. Also i have waited 24 hours after changing DNS but still no success.

When i try to verify the DNS - it says that everything seems ok:

To mention: I'm not using any microsoft NS? it that a problem?

I have noticed, that our domain is not set to "standard". The onmicrosoft is currently standard. I wanted to do this, but i get following error:

Saying something like: You can not use a external domain as primary. Choose a different domain and try it again. As mentioned - we are using exchange on prem. Would there be any issue when i set our domain to primary? 

Side Info:

Product License: Office 365 E3
The users all have as Usernames like "user@ourdomain.at"

e.g. danijel@dicom.at

Also I have noticed, that when i edit a user, the last entry is Skype for Business proberties.

But when i try to follow the link, i receive a blank page

[#2]

Hi!

Check through this thread

https://techcommunity.microsoft.com/t5/Microsoft-Teams/Some-users-cannot-chat-with-External-User/m-p...

Is SfB switched on for your users/assigned in the Microsoft 365 Admin Centre? I mean here within their licences? Need this for external communications

Let me know how it goes!

Best, Chris

[#3]

@Christopher Hoard when i check my user it says that the following license is active:
Office 365 E3
When i expand - it gives me a list of all products. Teams and Skype is active (but it says PLAN 2 on Skype - what does that mean?)

[#4]

Hi @Danijel_dicom

Thanks for confirming. Assuming you have done everything in this article

https://docs.microsoft.com/en-us/microsoftteams/manage-external-access

If it's still not working then I would raise it to support on a ticket. Would be good to know once the issue is resolved what the root cause of it was to help us in the future.

Hope that answers your question

Best, Chris

[#5]

Hi @Christopher Hoard 

Support Told me in Azure AD to activate

Onetime via Email for Guestuser. They told to wait 24 hours and then it should work. I'm very sceptical.

[#6]

Lets see how it goes! Let us know!

Best, Chris

[#7]

Good morning, 

i have same issues with the switch to Teams Only mode. Microsoft had to adjust the configuration in the backbone.In my tenant, everything was configured correctly. Please open a Microsoft Support case.