Here is a crazy fix that I found...
Seems that when you start Outlook the Ribbon is an inconsistent font to that of the Calendar (which in my case was the correct font). The fix:
- Open Calendar in a NEW window (right click on the calendar icon on the bottom left of the Outlook form - choose "Open in New Window")
- Close the Outlook Mail Window. This will leave the Calendar window the only active Outlook window
- On the Calendar Window - Right Click on the Envelope icon and choose "Open in New Window"
Your font will be restored back to the smaller font..
Crazy but true!!
Remember - if you can't explain it - Feature it!!