Add-ons are small programs the you can add to Thunderbird to extend its capabilities. There are literally dozens of add-ons available for Thunderbird. What can add-ons do? Here are some examples of the available add-ons:

  • Contacts Sidebar, which displays your contacts in a new pane in the Thunderbird window.
  • Signature Switch, which lets you easily switch between email signatures (say, because you have multiple email addresses).
  • Mail Merge, which lets you send bulk email. 

 Obviously, we can't cover every add-on in this manual. But we will be looking at the following ones:

  • Thunderbrowse
  • Lightning
  • Thunderbird Conversations
  • Attachment Reminder
  • Threadvis
  • Signature Switch

 But before we get to the extensions, let's take a look at how to add and manage them.