Skype for Business – The Exchange server won’t let us connect 

In Microsoft Skype for Business, you experience one of the following issue :

you can’t see the Conversation history on Skype client and you get this error – The Exchange server won’t let us connect. We’re working on fixing the connection. Your history, voice mail and Outlook features might be unavailable.

Resolution

1. Try to to check if there are subfolders under Deleted Items. If there are, remove them and try again
2. Check if the user had over 3000 folders in his mailbox
   Found with PowerShell: (Get-MailboxFolderStatistics -id user@contoso.com).Count
3. Try to Delete All Items under “Conversation History” on user outlook client.

SHMUEL H.