Configure Thunderbird

For many settings, there is a corresponding switch in the UI.

Some settings cannot be accessed in the UI, but it is still possible to change them from Thunderbird directly; you need to use the "Config Editor".

This is the equivalent of about:config in Firefox; the editor can be found in Settings › General (scroll down) › Config Editor.

Since the validity of such settings might change from one version to another, it is better to avoid it if possible.

Note that some values might be missing. This does not mean that those values are not supported, new values can be added anytime.

I believe this is straightforward, the wizard should be clear enough, and there are already enough guides, official and not.

I try to organize my emails in folders.

Emails from my work address go into a specific folder, emails from the bank to another, every mailing list has its own folder, and so on.

Most emails can be trivially categorized, others less, especially when you forward them, and some emails should be in two folders at the same time.

This is why I do not try to have too many folders, it makes searching more difficult if I do not know if the email should be in one folder or another.

By default, Thunderbird does not verify every folder for new emails. I realized it only after a while; why did my phone notify me about new emails and Thunderbird on the PC not?

You can click on every single folder and tell Thunderbird to always verify it for new emails, but it is error-prone, as there is no visual marker that shows in one window which folders will be verified automatically.

Through the "Config Editor", it is possible to tell Thunderbird to check all folders; and set the value for mail.server.default.check_all_folders_for_new to true.

For whatever reason, messages are shown in a list.

There is no indication that there are conversations.

For this reason, I find the tree view much better.

You can change the view in every folder by hand, or change once globally the default view through the "Config Editor".

Set mailnews.default_view_flags to 1.

The tree view shows how a conversation is structured, but…​ it is not that useful if you do not see your replies.

This is why I do not store the email I send in the "Sent" folder, but in the same folder I’m replying to.

Click on ≡, then on "Account Settings", then the account you want to configure, then click on "Copies & Folders", there is a section labeled "When sending messages, automatically:" and select both.

Never used them, always disabled them globally.

Click on ≡, then on "Account Settings", then the account you want to configure, and then "Return Receipts".

Select "Use my global return receipt preferences for this account", and then click on the button Global Preferences…​, and select "Never send a return receipt".

Text is easier to write, and understand, it requires less space, and is compatible with every email client.

There are two settings, I’m not 100% sure how they interact with each other.

Click on ≡, then on "Account Settings", then the account you want to configure, then "Composition & Addressing", and finally deselect "Compose messages in HTML format".

The second setting is located at ≡, then "Settings", then Composition, search for "Sending Format", and select "Only Plain Text".

I do not want to accidentally send an HTML email, for example, because I’m writing a reply with a quote. I would not mind an explicit toggle for activating HTML email (inline images and tables are useful), and there actual is one, but it is well hidden. You have to press ⇧ Shift and then click on New Message or Reply.

I always find this example good as to why I do not like top-posting:

I think the following is much more readable:

In particular, top-posting seems to encourage to never delete any content, because it is at the end of the email you are replying to, so you might not even notice you are sending dozens of pages of text (at least we are not printing them …​).

Also, once an email reaches a certain length, it might have multiple questions to answer or discussions happening in parallel.

It is often more practical to split the message and answer inline, Wikipedia provides a nice example so that I do not have to think about one

To change the default setting, click on ≡, then on "Account Settings", then the account you want to configure, then "Composition & Addressing", select "Automatically quote the original message when replying" and from the selection dialog "start my reply below the quote".

Similarly to how I prefer bottom-posting, as I read from the top to the bottom, I prefer my emails to be sorted from latest to newest.

You can configure every folder one by one, but it makes more sense to change the default value.

There is no graphical setting for it, but it can be done through the "Config Editor"; change mailnews.default_sort_order to 1.

The order is now the one I like for all folders by default, unless for those that I’ve already viewed in Thunderbird. For those folders, I needed to change the order by hand.

I always find it annoying when people have in their signatures "sent from my iPhone", or "mail verified with […​]"

Why would I care? Also, it means nothing, as everyone can write the signature it likes.

Personally, I have no interest in sending such nonsense, it also adds clutter if people simply reply and resend the whole message body, signature included, and do not trim it away.

The signature is at least visible. You’ll notice it, and act accordingly.

Emails also have headers that are normally not shown, and Thunderbird adds a "User-Agent" header, which is ignored by everyone.

Why would I want to let people know, through a hidden attribute, if I’m replying from my PC with Thunderbird, or with some other clients?

While setting up Thunderbird I noticed that general.useragent.override does not work anymore, the user-agent was still set. At least since one year when Thunderbird 115 was released.

The workaround is to set mailnews.headers.useMinimalUserAgent to false, but I still find it disturbing.

The user-agent is useless, and people who deactivated it with general.useragent.override had it turned on again after an upgrade.

It seems to be a recurring pattern for many desktop applications: provide UI with a lot of unused space/a lot of padding between elements.

I guess it might make sense for touch devices, where using the finger on the monitor is less precise than using a mouse or a keyboard, but considering that Thunderbird is mainly a desktop application, I’m not sure why it makes sense to have all that unused space by default.

Seeing in one go 8 messages or 17, without changing the font size or cramming everything together, makes a big difference.

To use a more "classic" layout, open the menu ≡, and click on the desired density.

It seems that I can avoid using an external addon for synchronizing contacts, as I used to.

CardBook still seems to offer some features that Thunderbird does not have out of the box (or I simply did not see them), but at the moment I’m happy enough to be able to use an add-on less.

The wizard seems simple enough, it does not need a more in-depth guide (at least here).

Thunderbird does not only add a user-agent but also another header that I do not like; the Content-Language, as described in this RFC ^🗄️.

I do not like it because my emails are written in different languages, and often in multiple languages, and it is not clear what the appropriate headers would be.

Either because I’m actually writing in multiple languages, or because I’m quoting something written in another language.

I feel that a document-wide header is not appropriate, if only 5% of the email is in, for example, french, should I also add french to the header? What if only single words, not even phrases, are in another language?

The second issue I have with this feature is how it is implemented.

It is easy to overlook the language of the document, and, as far as I remember, in Thunderbird, it is associated with the spell checker. I’m not changing the active language in the spell checker if I’m quoting something in another language, writing a two-sentence email, writing single words in another language, or writing in one language instead of two.

Thus the header will be wrong.

At that point, I believe it makes more sense to send no header and leave the receiver to read the content and determine by itself the language than sending the wrong header, and still leave the receiver to read the content and determine the language.

As described in in the bugtracker, there is no graphical setting for turning such header off; it can be done through the "Config Editor"; change mail.suppress_content_language to true.

After more than one decade (or even two) of reusing my configuration files, starting fresh showed me how much the default settings changed, and some things I did not need anymore.

I’ve surely overlooked something, after all this software has thousands of options, but even in its default configuration, I find it much better than other programs. And one reason is its availability on multiple systems.

Being able to change so many defaults has both its upsides and downsides, the main downside is currently the documentation, or at least being able to find what I want to do.