MAB File Extension
Mozilla Address Book
- File Type mab
- Developer Mozilla
- Popularity
- Application Mozilla Thunderbird
- Category Email Program Files
- Format Binary
What is a MAB file?
The MAB file extension is linked to Mozilla Address Book and belongs to the Email Program Files category, which includes 50 files.
The Mozilla Address Book (MAB), created by Mozilla, is one of file format they developed, and they also built 4 programs to support them.
MAB files are compatible with various operating systems, including Mac OS, Windows and Linux. When working with MAB files, you can rely on 2 programs, including Seamonkey and Mozilla Thunderbird.
Programs that support MAB files
How to open a MAB file?
If you can’t open a MAB file, it is usually because the necessary software is missing. To resolve the issue, select the right program from the list for your operating system. Then go to the official website of the developer, download the software, and install it.
Seamonkey and Mozilla Thunderbird are recognized as the most popular software solutions for dealing with MAB files. If you wish to install the latest release of Mozilla Thunderbird, visit the official Mozilla portal and download the edition that works on any operating system.
After installation, your operating system should automatically open MAB files with Mozilla Thunderbird.
Make Mozilla Thunderbird the default MAB viewer
Setting a default program by file type in Windows
- Right-click on your MAB file, then choose the "Open with" option and select "Choose another application" from the available options;
- Inside the popup window, scroll through the list of applications and specifically choose Mozilla Thunderbird as the application to associate with your MAB file;
- Check the "Always use this app" checkbox and click "OK".
Change the default app to open files on Mac
- Right click or use Control + Left Click on the desired MAB file to access a dropdown menu of actions;
- Select "Open in application" and click "Other";
- Next, at the bottom of the window, you will see the "Enable" menu, in which "Recommended Programs" is selected by default;
- In this menu, select "All Programs", then find Mozilla Thunderbird and check the box next to "Always open in the application."
How to edit a MAB file?
Editing MAB files requires installing professional software that lets you open and edit email program files. Online editors have more limitations compared to dedicated Mozilla Address Book programs.
Best MAB editors in 2026
Based on these criteria, we have prepared a list of available MAB editors.
| MAB Editor Software | Developer | Platforms | Overall Rating |
|---|---|---|---|
| Seamonkey | Mozilla | Windows, Mac OS, Linux | 4.8 out of 5 (41 review) |
| Mozilla Thunderbird | Mozilla | Windows, Mac OS, Linux | 4.2 out of 5 (41 review) |
Convert to and from MAB
If a MAB file is cumbersome, converting it to formats such as CSV, LDIF or other supported types can make it easier to manage.
Converting a MAB file may not fully retain all functionality, but it is generally possible to return it to the original format.
Convert MAB to other file formats
Converting Files to MAB Format
Finding answers to MAB file problems
There are some common issues with MAB files that can be resolved easily by making minor adjustments to your software. Below, you’ll find these issues along with practical troubleshooting tips.
What are the possible solutions to recover a corrupt MAB file?
Use a data recovery program to open the damaged MAB file and from the menu choose "Repair" function to start the repair process. Then wait for the recovery process to complete, which allows you to automatically repair corrupted email program files.
What are the warning signs that my MAB file may be corrupted?
Corrupted MAB email program files may show the following signs:
- Error messages appear during the course of working with the file;
- Editing the archive in Seamonkey is accompanied by slow performance or delays;
- The file does not open or opens with errors;
- Unexplained increase in MAB file size;
- File hangs or crashes in Mozilla Thunderbird or other programs;
What are the possible causes of Mozilla Thunderbird crashing?
Mozilla Thunderbird crashes can be caused by outdated software. Keep your Mozilla products up to date by installing the latest updates.
A computer restart is often the key to solving numerous common problems. That’s why, it is recommended to restart the computer before making any changes to the software settings.