Tag Archives: Mozilla Thunderbird

Thunderbird 115 Common Issues

Missing folders/emails in Unified Folders view

Close Thunderbird, go to the profile folder and delete virtualFolders.dat file and Mail folder. Start Thunderbird.

Exporting/Importing Message Filters

When you create a message filter, each filter is saved within the emails folder, in a file called msgFilterRules.dat, so when importing or exporting you’ll need to retrieve the file for every email address.


Thunderbird 115 Customizations

Hiding the number of messages under Message List Header

In Thunderbird Config Editor, find and change toolkit.legacyUserProfileCustomizations.stylesheets to “true”. Close Thunderbird.

In your profile folder, create a folder called “chrome”, then a file named “userChrome.css”, edit the file in any editor and add the following line:

#threadPaneFolderCount { display: noneĀ !important;}

Start up Thunderbird and it should now be hidden, if not, double check the config editor setting and the other steps if still further issue.

Changing tag background and font colours

Making sure Thunderbird is closed before you do any editing. Simply add on a new line, in the same file mentioned above.

/* Change the background color of tagged messages */
/* Tag name: Important */
treechildren::-moz-tree-cell(Timportant) {
    background-color: red !important;
treechildren::-moz-tree-cell-text(Timportant) {
    color: #FFF !important;

This should turn your emails, set with the tag “Important” to have a background colour of “red” (can be changed to another colour using HEX colours). Then the font colour to #FFFFFF (white).

Mozilla Thunderbird

An email client that’s open source and works on Windows. A great alternative to Microsoft Office.

I’ve been using Thunderbird for a few years now and it’s been improving and getting better since I first tried it out. The latest big upgrade has made some drastic visual improvements, making it a lot more visually stylish without making it look too clunky.

The biggest issue I have with it is the lack of an option to choose the column to show the “From” address being the reply-to address or at least some ability to see when you select on the email, the best method would be some checks to make sure it matches, making sure the sender is not spoofed, for example a lot of scam and phishing emails do this. Modern email clients should not have a simple feature like this missing.

On a personal preference, I’d like the client to be able to have the ability to switch profiles more easily or allow profiles to float in tabs.

How to fix emails suddenly displaying in code

You probably will never see this issue occur for you, but if like me you like to achieve quickly, sometimes while it’s indexing and the Windows anti-virus in the background may decide to scan the file and cause an error. Simple solution can be found in the link below.