Outlook keeps prompting for password
Good Article at Technet
Outlook keeps prompting for password could be caused by several reasons:
- Outlook is configured to prompt you for credentials
- Incorrect password cached in credential storage
- Required Authentication Settings for outgoing server and incoming server
- Outlook Anywhere is not configured to use NTLM Authentication
- Corrupt Outlook profile
- Slow or unstable network connection
- Antivirus programs
- Shared calendars
A forum article discussed this issue in detail, please follow the instructions in the article to troubleshoot the issue: