Rated 4 out of 5 stars

If your login password is not saved try to change exchange location url to https://DOMAIN\firstname.lastname@address.com/EWS/Exchange.asmx
After saving new url its should look like https://DOMAIN%5Cfirstname%2Elastname@address.com/EWS/Exchange.asmx and you should insert username as DOMAIN\firstname.lastname.
In my case it worked as I am domain user and my email address in fallowing form firstname.lastname@address.com.

This review is for a previous version of the add-on (0.12).