Betterbird: Expert Tips

Betterbird is really a Swiss army knife for mail processing. Here are some tips from our project manager to make your experience even better.

New Messages - Activity Manager

Out of the box, when Betterbird starts, it will show you the number of new unread messages and their folders.

If you have many folders an filters, the Activity Manager is also a nice tool to show you to which folders messages were moved. Betterbird opens the Activity Manager in a tab, so it doesn't get in the way. We suggest to keep it always open.

Multi-line view included since September 2021

Many people have asked us to finally implement a multi-line view, so we're happy to announce that this is now included in Betterbird. To enable it, deselect the subject column in the column picker of the message list/thread pane for a particular folder. There is also a global option View > Layout > Multi-line View On All Folders. Once you enable the global option, all folders will show in multi-line view. If you disable the global option, you still need to re-enable the subject column on the folders where you no longer wish to the use multi-line view. Multi-line view is highly customisable via userChrome.css, see below for details.

Language Packs

As of September 2022 we're shipping language packs for the languages we support. Betterbird language packs are specially made for Betterbird to cover its additional functionality. Thunderbird language packs are not compatible with Betterbird. To take advantage of language switching in the user interface provided in the settings, set the following preferences (will be the default from version 102.3.0): intl.multilingual.enabled - true and intl.multilingual.downloadEnabled - false, the latter to avoid downloading incompatible Thunderbird language packs.


There are thousands of add-on available for Thunderbird which will work 100% the same in Betterbird. Here are the ones we use:

ThunderHTMLedit - great to fine-tune the sometimes erratic HTML the editor produces.

Quick Folder Move - great add-on to find a folder quickly (Shift+G) or move messages (Shift+M).

Shrunked Image Resizer - essential for resizing images before sending.

Signature Switch - great to administer multiple signatures.

Lightning Calendar Tabs - let's you move through the calendar quicker.

Dictionary for recipient - if you write in different languages, store the language you want to use in the address book.

Sender Frequency - adds a column to the message list that lets you determine quickly you writes to you (or spams you) most.

There many excellent add-ons for specific purposes, like Mail Merge, TbSync for access to Exchange calendars, Emoji, Quicktext, FileLink (Dropbox, Box, WebDAV, Nextcloud and ownCloud) and many more.

A word of caution: with add-ons, less is more. Don't overload your system with too many add-ons. Some are poorly maintained or potentially not compatible with the latest application version. Check when the last update was made and handle with care if it's more than a year ago. Actively maintained add-ons will ship updates regularly. We think it's best to find the best add-ons that support your workflow and stick with them.


You can modify the CSS used for the display of the UI by adding a chrome/userChrome.css file. You need to set preference toolkit.legacyUserProfileCustomizations.stylesheets for changes to take effect. We are using this file (for Betterbird 102), striping ahead.

We're not great friends of customising everything, but this simple theme has stuck with us over the years.


You know that there will be dragons if you mess around too much with preferences, but here is a list of a few useful ones to explore:

mail.ui.display.dateformat.thisweekSet to 4 to get "weekday, time" display (recommended)
mailnews.display.date_senders_timezoneDisplays the sender's timezone in the header pane
mail.override_list_reply_toWhen true (default), overrides the Reply-To header (careful, religious war hiding here)
mailnews.reply_to_self_check_all_identWhen true (default), checks all identities in "reply to self"
mailnews.display.show_all_body_parts_menuEnables "View > Message Body As > All Body Parts"
mail.inline_attachments.textWhen true, text attachments are shown inline (recommended)
mail.html_sanitize.drop_conditional_cssWhen false, conditional CSS (media queries) won't be discarded
ldap_2.servers.outlook.dirTypeSet to 3 to enable access to Outlook address book (will cause slower startup)
mailnews.send_plaintext_flowedWhen false, plaintext won't be flowed (not recommended!)
mailnews.wraplengthLine length used for wrapping, 0 = no wrapping
mail.strictly_mimeWhen true, forces Quoted Printable encoding