After License change (E3 -> E5) all Outlook meetings are rescheduled

Copper Contributor

After adding Office 365 E5 licenses in the company, we now want to migrate users from Office 365 E3 to E5. But there is a problem: If we exchange the Office 365 E3 license with the E5 license for a user in the Microsoft 365 Admin Center, all Outlook/Teams appointments of this user are rescheduled. That means everyone gets a "Rescheduled" email!


Are we doing something wrong here? How can we change the behavior?


Thanks a lot


2 Replies
Not sure I've ever heard of this happening, are you removing the E3 license first, or swapping them in a single operation? In any case, best open a support case and report this.

hi @yschneider7

we have recently experienced this. it is likely because with E5, you get a phone conference ID that you wouldn't have had  previously (unless you also had an optional phone license). So outlook scans for future appointments without the conference ID and then adds it in and resends the invite.

The surprising thing for us is that the resent invites didnt show in the sent items in Outlook, but they were sent. They were shown in our email filter / handler - mimecast. they were definitely sent.


has anyone identified a way of preventing this happening?