While migrating a customer from Exchange 2010 to Exchange 2016, I had to create an Exchange Hybrid Deployment, because the customer wants to use Microsoft Teams. Nothing fancy and I’ve did this a couple of times. Unfortunantely the Hybrid Connection Wizard failed to create the migration endpoint. A quick check of the logs showed this error: Microsoft.Exchange.MailboxReplicationService.MRSRemotePermanentException: The Mailbox Replication Service could not connect to the remote server because the certificate is invalid.

Microsoft Teams got a big push due to the current COVID19 crisis and many of my customers deployed it in the past weeks. At ML Network, we are using Microsoft Teams for more than a year, and we don’t want to miss it anymore. Source: Microsoft We are running Exchange 2016 on-premises, currently CU16. We were missing the calendar tab in Teams since we started with Microsoft Teams. when you do some research about this issue, you will find many threads and blog posts, but these are the two key facts: