10-09-2025, 12:39 PM
In case of the error message "Thunderbird import MBOX files greyed out", reflecting a situation where the ImportExportTools NG add-on is not compatible with your current Thunderbird version, the first thing to do as a primary solution is to ensure that both your Thunderbird client and the add-on are fully updated to their latest, compatible versions. Check for Thunderbird updates under Help > About Thunderbird and let it install any available updates. For the add-on, go to Tools > Add-ons and Themes > Extensions, locate ImportExportTools NG, click the three-dot menu, and select Update Add-on.
If it still shows a compatibility error after the update, then the following steps involve attempting a fresh installation and looking for conflicts. Firstly, uninstall the ImportExportTools NG add-on, restart Thunderbird, and then download and install the add-on again from the official Thunderbird Add-ons page. If the option is still greyed out, you should make sure that you have set up an email account in Thunderbird because the add-on may not work on an empty profile. Besides that, try Thunderbird in Safe Mode (Help > Troubleshoot Mode... or hold Shift while launching) to check if the problem is caused by the conflict of another add-on.
If none of the solutions work, you might have to wait until the developer of the add-on releases a version compatible with your latest Thunderbird update or think about manually importing MBOX files straight into your profile folder, which is the way that is mostly used when the add-on is completely non-functional.
Pro Tips: Try using the MBOX Converter to directly import the files into the Thunderbird account.
If it still shows a compatibility error after the update, then the following steps involve attempting a fresh installation and looking for conflicts. Firstly, uninstall the ImportExportTools NG add-on, restart Thunderbird, and then download and install the add-on again from the official Thunderbird Add-ons page. If the option is still greyed out, you should make sure that you have set up an email account in Thunderbird because the add-on may not work on an empty profile. Besides that, try Thunderbird in Safe Mode (Help > Troubleshoot Mode... or hold Shift while launching) to check if the problem is caused by the conflict of another add-on.
If none of the solutions work, you might have to wait until the developer of the add-on releases a version compatible with your latest Thunderbird update or think about manually importing MBOX files straight into your profile folder, which is the way that is mostly used when the add-on is completely non-functional.
Pro Tips: Try using the MBOX Converter to directly import the files into the Thunderbird account.