The popular open-source email client RSS Thunderbird has just been updated to a new major release named Thunderbird 78. The new version of the leading open source email client comes with the option to add multiple email addresses per field, the chance to add colors to folders, a new message column with icons to select, and the option to minimize the client to the notification area on Windows.

The Thunderbird email client is the world’s most used open-source cross-platform email and calendaring client. It’s feature-rich, can sit on your desktop like a traditional app icon for quick access, and allows you to use any of your existing email addresses so that it’s only acting as a gateway through to your existing email inboxes. In years past, setting up clients such as these would be an annoyance — rarely would you be able to set them up easily — but Thunderbird 78 is very easy: all you need is your correct email address and existing password for the existing email address and then Thunderbird is able to give you instant access to your new mailing client.

Thunderbird 78 email client
The UI you see after opening Thunderbird 78. You can select your inbox from the left menu.

Thunderbird 78 allows you to add multiple email addresses per field, meaning you can now send an email to more than one recipient on a line. The previous versions of Thunderbird didn’t allow any more than one email address to be entered into the to, cc, and bcc fields in one line. This meant that if you entered more than one email address before, it had to create a new line for the entry, and subsequently, the area where you type the email would get smaller and even require scrolling if you entered enough email addresses. Now you can comfortably fit a bunch of emails and it will still be all on the same line.

You can also add icon colors to folders. This means if you select one of the colors, it will change the color of the folders in the sidebar of the client. You can change the color of your Thunderbird folders similarly to how you could change a folder when using Windows: right-click on the folder, select “Properties” from the menu, and then under the “General Information” tab will be the option to change the color. The root email folders are blue by default in Thunderbird 78; the rest are all black. The default colors are subtle which is what you want in a general sense, but you can now add a yellow or red folder if you have got one that’s important to stand out from the rest.

Thunderbird 78 has added a new way for you to select messages. By right-clicking on the header bar just above the emails when you have your inbox open, you can check the box for “Select Messages.” Doing so means you have an easier method for selecting emails you wish to use.

The Thunderbird email client is mostly used by Windows users still, and they’ve been looked after with a new option to minimize the client to the notification area in Windows. You still have the same standard minimize to the taskbar option like you would any other app, but Thunderbird 78 allows for the enabling of another option from its settings that will minimize to the notification area if you prefer it there.

The lists below include all of the new features, changes, and fixes that have happened over the course of the four beta versions of Thunderbird before we got to this official release that’s now available.

New Features:

  • Color customization of Folder Pane icons
  • Additional Enterprise policies
  • Calendar: Add event preview to ICS import dialog
  • MailExtensions: browser.identity API enabled
  • MailExtensions: Event fired when the user changes compose identity
  • Preference to disable OpenPGP functionality
  • MailExtensions: UI components for browser pages added
  • Chat: Direct message support for Matrix


  • OpenPGP support improvements
  • Various Address Book improvements
  • Dark mode improvements
  • Use scalable icons throughout Thunderbird
  • Account settings UI improvements
  • MailExtensions: Handle message attachments in browser.compose functions
  • Calendar: Location URLs are now clickable
  • Improvements to the location bar of a tab displaying web pages
  • Several improvements to vCard parsing
  • Various look and feel improvements
  • OpenPGP improvements
  • Various look and feel improvements


  • Various fixes for recipient address entry
  • Fixed width font not working in Write window
  • Accessibility improvements
  • Attachment pane in message preview layout broke when toggled or resized
  • Access key Alt+M for the attachment pane of the Write window not working correctly
  • Addons could not be removed
  • Print-progress dialog was disabled
  • “Clear Recent History” window did nothing
  • “Initially Show Attachment Pane” option was not working for Write window
  • Links in the Account Central content tab opened in Thunderbird as well as the browser
  • Order of columns in the thread pane was not persisted correctly
  • URLs in the message header display were not reachable via keyboard
  • Calendar: URLs in the event reminder dialog were not clickable
  • MailExtensions: Extension popup windows opened in a copy of the main window
  • OpenPGP support did not work on some Linux distributions when using the official builds
  • Thunderbird 78 did not run on Red Hat Linux 7
  • Anomalies appeared when inserting an image into the compose window
  • Chat: Copying from chat conversations not working
  • Addresses added to address book were not inserted into sorted order
  • Address book migration not working under certain circumstances
  • Chat: Own messages not displayed in private chats when server supports “echo-message”
  • MailExtensions: Tab was not defined in browser.menus.onClicked callback on out-of-window messages
  • MailExtensions: Select elements in action popups closed the window unexpectedly

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