How to Bulk Convert Thunderbird to Maildir File Format?

  

Mark Regan
Published: July 23rd, 2025 • 5 Min Read

Are you also searching for a reliable yet simple solution to convert Thunderbird to Maildir format? If yes, then this is the blog made for you only, since here we are going to cover every aspect of Thunderbird export to Maildir using manual and professional ways.

Thus, Thunderbird is an amazing email client, but it saves email in MBOX format, which contains batch data in a single file only. Due to this, users often seek a way for Thunderbird convert to Maildir as it stores email messages in a single file only, which ultimately protects data from uncertain loss or corruption. Therefore, to learn the possible reasons, manual methods, consequences, and professional solutions for Thunderbird export to maildir, read this complete blog to the very end and find the way that works for you.

Why Users Want to Convert Thunderbird to Maildir?

There are multiple situations or conditions that make a user convert Thunderbird to maildir format. However, some of the most prominent causes for the same are as follows:

• Maildir is a single email message file format that helps in making Thunderbird and the system’s performance fast and less corruption-prone, unlike the Thunderbird-supported MBOX files. 
• Also, maildir files offer enhanced data security and authenticity, as corruption in one maildir file does not affect mass email messages. 
• In addition to this, users also want Thunderbird export to maildir so that they can perform quick and easy incremental backup whenever needed.
• The maildir file format also prevents file-locking problems, which are often encountered in the MBOX format. 
• Apart from this, if the user wants to import Thunderbird data to Linux-based email servers like Qmail, Dovecot, Postfix, etc., then they also need a solution to convert Thunderbird to maildir. 
• Last but not least, exporting Thunderbird emails to a maildir file also allows the user to easily view, read, share, or edit the data on various devices.

Thunderbird Export to Maildir Format Manually

The quick and conventional way to convert Thunderbird to Maildir is not so reliable due to its multiple restrictions. However, have a quick look at them to learn the indirect yet free way to export Thunderbird emails to Maildir. 

1. Firstly, open Thunderbird on your device. 
2. Now, click on the menu icon. 
3. From there, choose Settings and click on the General tab. 
4. Next, scroll down and select “Config editor”. 
5. Further, click on Show All and search for “mail.serverDefaultStoreContractID”.
6. Once found, double-click on it to change the value to “@mozilla.org/msgstore/maildirstore;1”.
7. After this, restart Thunderbird and again click on the Menu icon. 
8. Now, choose Account Settings and select “Server Settings” from the left panel. 
9. Then, scroll down and make sure that Maildir is chosen as the storage option. 
10. Once done, open an email account that is old and has MBOX files. 
11. Click on any of the emails, drag and drop them to the maildir folder. 
12. Further, download the ImportExportTools NG plugin on Thunderbird. 
13. After this, export that email as an EML file. 
14. Finally, import EML files into an account that is Maildir-based. 

Why the Conventional Solution is Unreliable?

• The manual method to convert Thunderbird to maildir is very complex and confusing. 
• It is lengthy and thus consumes a lot of user time, effort, and energy. 
• The drag and drop step of the manual method to convert Thunderbird to maildir may not maintain the data authenticity in terms of formatting. 
• This method is prone to error and can lead to permanent data loss or alteration. 

How to Professionally Convert Thunderbird to Maildir?

The manual method for Thunderbird export to Maildir is very complicated and has various restrictions which hamper user productivity and data security. Therefore, to reliably do the Thunderbird export to Maildir, professionals always use and recommend an automated tool such as BitRecover Thunderbird Converter solution. It is easy, quick, and trustworthy to share the crucial information and do the export of Thunderbird bulk emails in maildir format effortlessly. The quick steps to use this solution are as follows:

1. Install and run the solution on your device.
   
   
2. Now, select the Thunderbird data using the given selection modes.
   
   
3. From the list of 30+ saving modes, choose Maildir.
   
   
4. Then, give the saving location and choose naming format. 
5. Finally, click on Convert to process the Thunderbird to Maildir conversion. 

Benefits of Using the Professional Tool

• It is quick and reliable since it supports bulk action and saves user time, effort, and other resources. 
• The automated tool has multiple data selection modes which help in a decluttered output. 
• The file naming and file saving location option helps in managing the output and getting quick access to it. 
• It supports all the elements of the file including header, footer, attachments, multimedia, and even folder hierarchy. 
• This utility has 30+ saving modes which allow the user to easily convert, backup, fix, and transfer Thunderbird data accordingly. Thus, with this solution users can easily convert Thunderbird to PST, PDF, EML, Gmail, Outlook, etc. 
• Last but not least, this software also has a demo edition which is completely free of cost and lets the user try the tool before getting the licensed edition. 

Conclusion

In this blog post, we briefly highlighted the best way to convert Thunderbird to Maildir format. However, we came to know that the conventional way has lots of limitations, and that is why experts always suggest using an automated solution like the one mentioned above. Therefore, the professional solution is very compatible as it runs on all devices and their editions, including Windows and Mac OS. Hence, it is the best alternative for Thunderbird export to Maildir due to its ease of use and data authenticity features.