Skype/Teams Coexistence/Interop: What's with the emails sent to Skype Users?


This week we started piloting our Teams upgrade from Skype For Business (S4B) online.  For each of the policy we changed their settings using the Grant-CsTeamsUpgradePolicy -PolicyName UpgradeToTeams CMDLET.  Everyone else is in Islands mode.  Teams<->Teams communications seems to be working as expected.


HOWEVER:  It's now been several days and I'm now getting reports from a fair number of users that when a Teams user tries to IM or meet with a S4B user, the following things happen: 

  • When a Teams user attempts to IM a S4B user, instead of a chat session, the S4B user receives an email with the familiar Teams cartoon family.  It tells them that UserXYZ is trying to reach you via Teams, and provides a slew of links/buttons for them to DL/Install Teams and start communicating with them that way.  HUH?
  • I've confirmed that S4B users can DL/Install and start using Teams, but this is not what we want. 

Teams-Skype Email.png

  • Cross-platform/app presence doesn't work from either side.  In the SS below 'Kathy' is the Teams user and 'Karen' is the S4B user in Islands mode.

cross-platform presence.png















  • We can't support an uncontrolled companywide rollout of this yet, not to mention that our Legal/Security depts haven't fully signed off on it yet.
  • I need to be able to:  
    • Disable these e-mails
    • Fix the IM/Presence Interop problem.

 Most enterprises need to be able to control their rollouts of apps across the company, and to have this happen is simply unacceptable.  

39 Replies

It sounds like they are not in TeamsOnly mode. When the upgraded user opens their S4B do they get the information that they have been upgraded to Teams? Have you tried messaging them from Skype 4B? (Skype4B->Teams) Does it work?

This is because you have it set to island mode, your users in Teams are sending messages to Teams because the other users have both Teams and Skype in island mode. You need to set the org to Skype Only, and then set your users Teams only that are Teams only.
I disagree with that. On default organizations are on Islands mode, and if you set people to TeamsOnly they can coxist. If you set the organization is SkypeOnly, people can't user both Skype and Teams (unless individual person has been set into other upgrade policy)
They cannot coexist on island modes. That's the point of island mode. You have to have one of the other for the routing to work properly otherwise they both sit stand alone from each other.

For the pilot users it was simply:  Grant-CsTeamsUpgradePolicy -PolicyName UpgradeToTeams -Identity $_.UserPrincipalName

Confirmination also via PS:  get-csonlineuser -Identity $_.UserPrincipalName | select displayname,TeamsUpgradePolicy,TeamsUpgradeEffectiveMode,WhenChanged,windowsemailaddress,userprincipalname

Things looked as they should, and yes users were getting the 'you've been upgraded to Teams' popup in S4B, and are redirected to Teams.

Please check out this recent blog post pertaining to coexistence if you haven't read it. It should clear some things up.

The current documentation says that Interop policy setting is no longer needed. (I edited the post to remove the obsolete information about interop policy)

Bottom line here, you can't use Island mode on all your users, they need to be skype only, then your users that want to pilot and use Teams can stay set as they are with Teams Only. You need to go change your org setting to Skype Only.

This will keep everyone else in Skype, and Teams pilot users in Teams. The reason the Skype users get the Teams e-mail because you are in islands and Teams users send the message to them in Teams goes to their Teams account.

The problem is because you didn't do this first, you might have issues once you make this change since those users are already in and using Teams in addition to Skype. Never have gone back after the fact to see how it handled a transition like that.

Chris Webb - you are right. I think this was changed when the last interop change was rolled out. Prior that Islands mode worked ok, now in Islands mode the communications land on the same tool they were sent from (unless the receiver is in TeamsOnly, in which case the messages land on Teams instead of Skype.
Yeah Islands or "Legacy" whatever you want to call what Islands used to be, had an option to message skype users from inside teams, but it was ugly and you would have duplicate contacts in the system etc. Pretty sure that changed with the new interop modes when they got pushed.

I and my team were one of the 1st in my org to go to UpgradeToTeams, and the email notifications were not seen/reported.  InterOp IM/Chat worked fine, which is why I felt comfortable moving forward with the pilot.  If the emails suddenly started appearing with my S4B users I would have put the brakes on and completely redesigned the rollout strategy.  That's why it took me so much by surprise.


I didn't see anything in the documentation about the email notifications.  I also watched the Ignite sessions on upgrading, and NOTHING was mentioned about this.  In fact, it was just the opposite.  Full 2-way transparency was the law.  SS's from slide decks:  



Yea and one has to be Skype only and the other Teams only for the above to work. What might have happen is your coexistence modes got forced, or updated on the back end where legacy settings no longer get recognized. But if you are in fact on islands for the org this is why it's happening. You may have had manual interop policies in place using the old cmdlet routing your original pilot users differently.

Anyway, check what you have, because the current method is Skype Only and Teams Only for your scenario, islands will not work that way since it's meant to be 2 independent setups with no inter op. Why it just switched or what not I can't answer that, I just know some of the legacy modes and things tied to it were set to no longer work after a certain point and it could be related.
This was changed after Ignite session - about a month ago.

I have to admit, that didn't think that this change also affected the communication. Now that Chris explained it - it makes a sense.

@Chris Webb If we set all users to Skype-only, then set Teams pilot users to Teams-only individually, what happens for the Teams-only users when they need to attend a recurring (let's say weekly) Sfb meeting?  Are they able to join using the Teams client?

no, it will still use the skype client to join skype meetings. Even thou it disables IM functionality, it still can be used for meetings and will do so accordingly.

Our people have been going round and round with MS support on this. We tried the Skype Only/Teams Only scenario and it didn't work. But we've got a wrinkle that others might not have - we're Skype On Premise - we don't have licensing for Online. Skype Only/Teams Only won't work with on premise Skype. 


So we're changing our plan for rollout. Since we have less than 100 who actually chat, we'll be rolling out Teams to everyone and just do training on Chat, screen sharing, and what people used to do in Skype. Then start training on the Teams parts... Not what we wanted to do but better than Islands mode. I liked the way it used to work!

You might want to try one SfBWithTeamsCollab or SfBWithTeamsCollabAndMeetings. I believe these can only be set in PowerShell. This way you can achieve the desired outcome, without disabling Teams for the Skype users.


I haven't played with these modes myself, but hopefully, they may help you.

The new coexistence modes will support your scenario, but don't know how long those will be. Also being on-prem def. makes it much harder. The issue you will run into thou, Skype Online license is required to be on for Teams to work, so you might have to do some testing around that.
Last I checked those modes still were not supported / functioning. Def. something to try.