- You receive a message in Lync that says it cannot connect to Exchange.
- You're repeatedly prompted to provide a user name and a password to connect to Exchange.
- You may also receive the following message: Credentials are required
- Calendar and Free/Busy information from Outlook
- Exchange Web Services (EWS)
- Response Group Service
- Address Book Service
Article ID: 2298541 - Last Review: Dec 16, 2016 - Revision: 1