What is it?

The meeting migration service is a back end tool which monitors users  meetings in 365. MMS is not to be confused with the Meeting Migration  Tool (MMT) which is used to update users meetings when the user is homed  on either Lync Server or Skype for Business Server and requires a  desktop application to be ran. See here for more info…

How does it work?

MMS works by looking at the existing created meetings for users. Once  one of the bellow changes is executed the request to migrate is placed  in a 90 minute queue. The click to join URL, conference ID and also any  PSTN information in the users future meetings are then updated to the  details of the new provider.

The following are the instances which trigger MMS:

  • ACP (Audio Conferencing Provider) change
  • Enabling or disabling an Audio Conferencing license
  • Enabling or disabling the Audio Conferencing feature
  • A users conference ID change occurs


  • Users mailbox needs to be located in Exchange Online


  • If the meeting information block has been modified by the user then these changes will be lost
  • Anything outside of the meeting information block will not be lost
  • Meetings ¬†will only be updated if they were scheduled using the SfB/Teams add-on ¬†in Outlook. If the user copied the meeting information into another ¬†meeting then this will not be updated by MMS
  • Any content attached to the meeting (eg whiteboards, polls etc) would need to be recreated/backed up
  • Shared ¬†meeting notes in the calendar item and also from within the Skype/Teams ¬†meeting also will be overwritten. The meeting notes stored in OneNote ¬†will still be there as the only change is the link to the notes
  • Meetings with more than 250 attendees will not be updated by MMS

End User Experience

Once MMS has completed (usually takes around 10 minutes) an update  will be sent to all the invited users of the meeting that has had the  information  changed. Due to this the invited users will start to receive accepted meeting notifications,  this could potentially be confusing so some sort of communication  should be sent to the users prior to the change would be advised.


  • Pending
  • Indicates that MMS has scheduled a job to update the calendar entries for the user

Manage MMS

To manage MMS we have a few POSH commands which can be run.
Get-CsMeetingMigrationStatus -SummaryOnly
^^^ Outputs a summary of the migration process.
Get-CsMeetingMigrationStatus -UserId "karl@techramble.blog"
^^^ Outputs the progress for a specific user by filtering using the users UPN.
Get-CsMeetingMigrationStatus | Where {$_.State -eq "Failed"} | Format-Table UserId,LastErrorMessage
^^^ If there is an error the following command can be ran.
Start-CsExMeetingMigration -Identity karl@techramble.blog
^^^ This command can be used to manually start the MMS process for a user.

Any questions leave a comment!

Cheers ūüėé