User may receive the error 'Error: Microsoft Exchange Server Unavailable' when trying to set up Outlook after Outlook Anywhere integration has been enabled in the hosting environment. This may occur when using Outlook 2016 Exchange server.
If your organization is using Outlook 2016: We are currently evaluating this issue. Until such time as a solution is found, please use SMTP Relay integration.
For all other supported Outlook versions: Verify that your information to set up Outlook Anywhere (RPC over HTTPS) integration is still correct and that there have been no changes to this.