Recently I had to use an Office 365 mail account with Mozilla Thunderbird. For some reason, Office365 domains are not recognised by default by Thunderbird and such the automatic configuration doesn't work. This took quite a while to debug, as Thunderbird has no built in options for connecting to Exchange servers, hence you have to set up IMAP and SMTP.
Below is my working configuration at the time of writing. It may change with updates of Office 365, but I hope this helps if you're having problems!
Step 1 - New Account
File->New->Existing mail account
Your Name: <The name you wish emails to be sent from> Email address: [email protected] Password: xxxxxxxx
Step 2 - Manual Setup
Click Continue followed by Manual Config and enter the server settings below:
Incoming Mail: Type: IMAP Server: outlook.office365.com Port: 993 Username: [email protected] Security: SSL/TLS Authentication method: Normal password Outgoing Mail: Type: SMTP Server: outlook.office365.com Port: 587 Username: [email protected] Security: STARTTLS Authentication method: Normal password
Step 3 - Finish setup
Click Re-test followed by Done