SBD files are data files primarily associated with Mozilla Mail Subdirectory. These files are user-defined that means these files are created when we create a subdirectory in our Thunderbird application. As Thunderbird provides us the message management feature, we can manage our messages by creating subdirectories.
The SBD files are supported by Mozilla Suite.
Launch a SBD file on your PC, by double clicking it. If your file association are set up correctly. The application Mozilla Thunderbird will open .sbd file. If you have the correct application, but SBD files are not yet associated with that application. In this case, when you try to open an SBD file, you can tell Windows which application is the correct for that.