To resolve this issue, first determine whether Outlook is connected to an Exchange Online server, and then use one or both of the following troubleshooting steps, as necessary: This issue may occur if Outlook isn't connected to a Exchange Online server. When you try to invite participants to a Skype for Business Online (formerly Lync Online) meeting in Outlook, the meeting invitations aren't sent as expected. Invitations are not sent from Outlook when you try to schedule a meeting in Skype for Business Online
