Issue: Thunderbird fails at the authentication stage of adding an 0365 Exchange email account. Your email address and password are confirmed and correct. The issue is Exchange requires an Active Sync or EWS Exchange Web Services connection which ThunderBird doesn’t natively support.
Solution – install the ExQuilla for Microsoft Exchange and Exchange EWS Provider Add-Ons. ExQuilla connects email and contacts, Exchange EWS Provider connects the calendar.
Step 1Â Email and Contacts – Install & Configure ExQuilla
- Tools > Add-Ons
- Search for and download the ExQuilla for Microsoft Exchange add-on. It does not show up until you click “show all results”
- Go to Tools >Â ExQuilla for Microsoft Exchange
- Enter your email address and password (check “remember password”
- Click the “do auto discover” button which should automatically configure your account via Exchange Web Services (EWS) –Â https://outlook.office365.com/EWS/Exchange.asmx
- Click Next
- Done!
— - If you encounter any issues (went smoothly here!)
Step 2 Calendar –  Download, install & configure Exchange EWS Provider
- Download the Exchange EWS Provider XPI file – exchangecalendar-vx.x.0.xpi
- Install: Tools > Add-Ons > Gear icon > Install Add-On from File…
- Select the the XPI file > click Open > click Install Now > Restart ThunderBird
- Create new Calendar: Â File > New > Calendar
- Choose On the Network
- Choose Microsoft Exchange
- Enter name and email address
- Choose Hosted Exchange
- Configure New Calendar
- * The “Use Exchange’s autodiscovery function” did not work for me
- Enter Server URL: https://outlook.office365.com/EWS/Exchange.asmx
- Enter username and email address (username is typically your full email address)
- Click Check Server and Mailbox
- Click Next & Finish
- Enjoy!