Rated 5 out of 5 stars

Works good if you only have one email account, but if you need Owl for more then one address, it doesn't work. I have multiple licenses for my company, so that is not the issue.

Update - Works great after using EWS on the other accounts. Sorry for the inconvenience.

This review is for a previous version of the add-on (0.7.7.5). 

This is a limitation of the Microsoft protocol, not of Owl itself.
You can try to set up the account using EWS in the Owl settings. EWS allows several accounts at the same time.