Switching to Thunderbird from Apple Mail

A long time ago, and for many years, I used Thunderbird as my desktop email client. I don’t remember when I stopped using it. I know I wasn’t using it when I bought my MacBook Air in 2011, so it was roughly nine years ago, if not longer. My wife kept using Thunderbird, and every time I saw it, I wasn’t even sure it was under active development; it never seemed to change.

What I need from an email client

I tried newer email clients over the years, but settled on Apple Mail because it was simple and met all of my needs:

  • Hierarchical folders displayed in a sidebar
  • Rules to process mail as it’s received
  • Smart mailboxes to automatically organize mail
  • Presumably under active development

At some point during the years that I used Mail, I started using rules to flag financial emails (bills, bank statements and receipts). I got by with colors and flags, which are the only options available natively. In January, I decided I really didn’t like the color/flag system anymore. I really wanted tags, but Mail has no native tag feature. I searched for a solution and found a capable but expensive add-on called MailSuite. I liked the tagging capability added by MailSuite, but it costs $60, which I couldn’t justify spending just for tags. (It has other features, but I wasn’t using them.) There’s also the danger that, since it’s an add-on to a native Apple app, it could be rendered useless by future changes to Apple’s APIs.

Around the same time, I read this post on the Thunderbird blog and realized that Thunderbird was alive and well. It has native tags, so I decided to give it another try. I alternated between using Thunderbird and Apple Mail for a while, but before long I was using Thunderbird exclusively.

Thunderbird’s key features

I found that Thunderbird satisfies the four main requirements I listed above, and it has several other features that made it the clear winner.


Tags are the main feature that brought me back to Thunderbird. If I need to save an email for future reference (an airline reservation, for example), I’ll file it in a folder. But many emails don’t need to be saved permanently; they need attention temporarily, but not always immediately. I use tags and rules to categorize and triage those emails, and it’s much easier to read a tag than it is to remember what a color means.

Tags are created under Preferences > Display > Tags.

Thunderbird tag preferences

The one thing I don’t like about Thunderbird’s tags is that you can’t change the order of the tags, and the order determines the shortcut key for each tag. (There’s an 11-year-old bug for this very issue.)

Tags can be assigned to messages in a number of ways. You can right-click a message and select the tag from the Tag submenu.

Tags can be assigned from a message’s context menu

With the message selected, you can click the Tag button in the Mail Toolbar, or you can just press the keyboard shortcut for the tag. The shortcut for each tag is shown in the menu. (The shortcut key is determined by the tag’s position in the tag list.)

Tags can be assigned with the Tag button

In addition, message filters can automatically assign tags based on conditions that you define.

Tags can be assigned automatically with message filters

You can also assign a color to each tag. Messages assigned a particular tag are displayed in that color. If you have the Tag column displayed in the message list pane, the message’s tags are displayed there.

If the Tag column isn’t displayed, right-click any column heading in the message list pane and select Tag from the menu.

Configuring the columns in the message list pane

Tags can be used in Saved Searches (Thunderbird’s analogue to Apple Mail’s Smart Mailboxes). I use this feature to show all of my financial emails (and only those emails) in one folder.

A Saved Search using tags

Privacy and security

Thunderbird provides a couple of useful privacy and security features by default. First, remote content in messages is blocked by default. Images and other content loaded from a remote server are a common way to track if a specific person has opened an email, as well as other information you may not want to share. (This isn’t limited to just the images you see; some emails contain very tiny images called tracking pixels.) Since Thunderbird blocks remote content by default, you’re protected from this tracking mechanism.

If you click the Preferences menu in any message where remote content was blocked, you’ll see the origin of all remote content in the message, as shown in the image below. From the menu, you can display the remote content in the message (Show remote content in this message), allow remote content from one or more of the originating domains (e.g., Allow remote content from cms.qz.com) or allow remote content from all of the sender’s messages (e.g., Allow remote content from [email protected]).

Remote content preferences in a message

Although I wouldn’t recommend it, you can also allow all remote content by enabling the Allow remote content in messages setting under Preferences > Privacy.

Thunderbird privacy preferences

I really like how this setting is presented. Both its wording and the fact that it’s disabled by default make it clear that this is an explicit opt-in setting. Even better, there’s a link that provides more detail about this setting and why it’s important to your privacy.

Apple Mail has the same feature, but I like Thunderbird’s functionality and presentation better. In Mail, it’s under the Viewing preferences. While that makes sense, I think framing it as a privacy setting is a better approach. Thunderbird also allows more detailed control over remote content. For example, Apple Mail loads either all or none of the remote content. You can’t allow it per origin or per sender as you can in Thunderbird.

The second feature is one that I haven’t seen in any other email client. If you click a link in an email, and the link text doesn’t match the actual link location, Thunderbird displays a warning and asks you which link you actually want to follow.

Link mismatch warning

Preventing messages from being marked as read

There’s one other feature that I really like: I can prevent messages from being marked as read unless I specifically mark them as read. Sometimes I want to preview a message quickly and then come back to it later; in that case, I don’t want it marked as read. But Apple Mail marks a message as read immediately, even if you view it in the preview pane, and there’s no way to disable it. Thunderbird has an Automatically mark messages as read setting under Preferences > Display > Advanced. The setting can be disabled so that messages are never marked as read unless you mark them as read.

Apple Mail features that I miss (and a few workarounds)

It wasn’t a big change to switch to Thunderbird from Apple Mail; both are standard desktop email clients with the same basic features. However, there are a few things I miss about Apple Mail. Fortunately I was able to find workarounds for most of them. The workarounds aren’t necessarily elegant, but they get the job done. These are minor inconveniences that I’m willing to put up with because Thunderbird has really useful features that Apple Mail lacks.

Keyboard shortcuts

Apple Mail has the ⇧⌘R keyboard shortcut to mark a message as read or unread. Thunderbird doesn’t have a keyboard shortcut for this. While it would be possible to create a keyboard shortcut in macOS’s keyboard preferences, it would require two shortcuts: One for mark as read and one for mark as unread. (Update - July 18, 2020: Someone actually read this post and let me know that Thunderbird does have a keyboard shortcut to mark a message read or unread: M. And there are many other shortcuts that aren’t exposed in the menus.)

Instead, I used Keyboard Maestro so that I only have to remember one key combination (and it’s the same one I’ve been using for years in Apple Mail). If the As Read menu item is enabled, ⇧⌘R selects Thunderbird’s Message > Mark > As Read menu item. Otherwise it selects Message > Mark > As Unread.

Keyboard Maestro macro to mark a message as read/unread

I made a few other shortcuts just for convenience, rather than to replicate Mail’s functionality:

  • ⌥⌫ to mark a message as read and then delete it.
  • ⌥F to open Message Filters.
  • ⌥A to open Account Settings.

Message filters

Message filters, which are called rules in Apple Mail, are created per-account in Thunderbird, whereas in Apple Mail all rules work in all accounts. Even though I only have two filters at the moment, I didn’t want to recreate and maintain them for each email account, especially since that list of rules may grow over time. (For several reasons — including a couple of merchants who, in the year 2020, can’t successfully process an email address change — I’m monitoring multiple accounts for financial transactions.) Fortunately, there’s an extension called quickFilters that enables copying filters from one account to another. It would be better if Thunderbird just had native global filters, but the extension gets the job done.

User interface

Thunderbird still looks a lot like it did 10 years ago; its user interface hasn’t seen a lot of updates, and it isn’t as polished as Apple Mail’s. This is especially obvious if you use macOS in dark mode. Thunderbird doesn’t adjust its interface to match the operating system’s appearance. A dark theme can be enabled under Preferences > Extensions & Themes > Themes. However, some parts of interface, such as the preferences screen and context menus, don’t conform to the dark theme. Hopefully, since Thunderbird is actively developed now, the interface will get a refresh in the future.

Final thoughts

Minor inconveniences aside, I’ve been happily using Thunderbird for several months now, and I’m glad to see that it’s being actively developed and improved. It’s a solid, uncomplicated email client that does everything I need it to (with a few minor workarounds).