To set up Thunderbird to check your Office 365 email account, follow these steps:

  1. Click Skip this and use my existing email on the Welcome to Thunderbird screen to go to the Mail Account Setup. If you have an existing email account configured, then click on Local Folders in the left hand sidebar.
  2. Click on the Email option under Create a new account in the right hand panel.
  3. Enter your name, full College email address, and College password.
  4. Click Continue and wait a while. Thunderbird will fail to find the settings on your email account. This is expected.
  5. Enter IMAP Server hostname: outlook.office365.com Port: 993  SSL: SSL/TLS and Authentication: Normal password in the Incoming section. 
  6. Enter your College username followed by @ic.ac.uk e.g. jb12@ic.ac.uk in the Incoming section (this is not your email address).
  7. Enter SMTP Server hostname: smtp.cc.ic.ac.uk Port: 587 Connection security: STARTTLS and Authentication method: Normal password in the Outgoing section. 
  8. Enter your College username only (not followed by @ic...) in the Outgoing section.
  9. Click Done to complete the account set up.

Your email account is now ready to use.

Please be aware that while we will endeavour to support Thunderbird, it is not a core college service and therefore we cannot guarantee stable use.

Steps for fixing known errors:

If after clicking Done, your email does not appear, please try:

  • In the Tools menu, you will find Options. In options there is a button called Attachments.
  • Please locate the association for the file type and delete it.
  • Next time you ask Thunderbird to open a file of that type it will ask you what to do with the file. You will need to select the correct application. You can also click Save and have Thunderbird remember exactly what to do with that file type.


If the attachments are being removed from emails then please try the following:

  • Currently there is an add-on that allows the attachment to be displayed, which comes directly from Mozilla