Outlook not syncing with the server can be caused by many different issues. Try the following steps to correct the issue.
- Check your network connection (If you are reading these remediation steps you can rule this out)
- Reboot your computer
- Toggle the 'Work Offline' option under send and receive. This typically resolves issues relating to working onsite and you happen to move around campus hopping to different nodes on the wifi network.
Toggle Work Offline - Remove your account and add it back within the Outlook Client. Pay special attention to the "important" box in the article linked below.
Removing/Adding Account Outlook Application
A backup method to accessing your email and calendar is accomplished via Outlook Web Access. While this method is not preferable by most it will keep you connected in a pinch.