Office 365: Configuring Thunderbird

This article is for Duke University users *only*. By policy, Duke Health users cannot use IMAP/Thunderbird to connect to their email.


Before proceeding, please note that there are a number of special considerations for using Thunderbird with Office 365.

Note: Thunderbird is not supported by Duke OIT. We recommend users use Outlook or OWA ( 

  1. Open Thunderbird.
  2. The Mail Account Setup dialog box will open the first time that you open Thunderbird. If the Mail Account Setup dialog box doesn’t open, do the following:
  3. Click Create a new account.
  4. A Welcome to Thunderbird dialog appears asking if you would like a new email address. Click Skip this and use my existing email.
  5. A Mail Account Setup dialog box appears. In the Mail Account Setup dialog box, do the following:

    •  In the Your Name box, enter the name that you want to appear on the “From” line in your outgoing messages (for example, “Jane Doe”).
    •  In the Email Address box, enter your Office365 e-mail address.

      • For University users, this should be
      •  In the Password box, enter your NetID password.
  6. Click Continue.  A “Looking up configuration” message appears for a few moments.
  7. Click Manual config. Incoming settings should be as follows:

    • Select IMAP from the drop down.
    • Server host name:
    • Port: 993
    • Connection security: SSL/TLS
    • Authentication: Normal password
  8. Outgoing settings should be as follows:

    • Select SMTP from the drop down
    • Server name:
    • Port: 587
    • Connection security: STARTTLS
    • Authentication: Normal password
  9. For username, type where netid is your Duke NetID.
  10. Click Done when you’ve finished viewing or changing the settings.

A Checking password message appears; this may take a few seconds. When that is done the screen will go back to Thunderbird, and you will see the mailbox listing on the left hand side. Thunderbird will connect to the Office 365 email system and begin to download your email. Please be aware that this may take some time, especially if you have a large amount of email in the system.


  • If you would like instructions on using LDAP with Thunderbird for Address lookup click here.