How to Export IMAP Emails to MBOX File Format Easily?

Approved By Rollins Duke

Published On September 26th, 2026

Reading Time 8 Minutes Reading

Quick Answer: When one needs to export IMAP emails to MBOX file format, he/she is often backed with the idea of archiving emails or migrating into a different webmail client such as Thunderbird or Mac Mail. Also, one should keep in mind that since almost all webmail services run via IMAP, emails remain stored in some other place until downloaded to the local machine. In order to perform the export, one usually has to use a specialized email migration tool or email that has been set up to work with your IMAP email settings. Once the configuration is finished, it is possible to archive or export your folders directly into MBOX format.

Reasons to Export IMAP Emails to MBOX

Protect your vital cloud mailbox data by having an independent and offline copy on your hard drive.
Transfer all your email history from one desktop client to another like Thunderbird to Apple Mail or Eudora.
Obtain universal support for your files in various email interfaces or applications for long-term access to your data.
Retain your existing data structure for the exports into MBOX format.
Inspect your important historical communications whenever you want even without an Internet connection.

How to Export IMAP Emails to MBOX Manually?

Manually exporting your IMAP mail in the MBOX format is an excellent method of performing a local backup, transferring your email history, or even freeing up some server space.

Most email programs do not have this capability right out of the box, which means that the safest manual method involves using an application such as Mozilla Thunderbird and a free add-on developed by the community.

Prerequisites:

You have Mozilla Thunderbird installed on your PC.
You have the access information for your IMAP account (email and password, and the settings for both incoming and outgoing mail).

Step #1: Set up an IMAP account in Thunderbird

Launch the application Mozilla Thunderbird.
Click the menu button (three horizontal lines in the right top corner) and go to New > Existing Mail Account.
Fill out the form with your name, IMAP email, and password, and hit Continue.
The application will try to figure out your server’s settings on its own. Ensure that it has chosen the “IMAP” option instead of POP.
Hit Done to start syncing your mail accounts and downloading emails from your IMAP account.

Step #2: Install ImportExportTools NG Plugin

The reason for this is that because Thunderbird does not have the ability to export the folders into the standard MBOX files in a single click, we need a lightweight plug-in:

First, open Thunderbird’s Menu icon and click on Add-ons and Themes.
In the Add-ons Manager page, type ImportExportTools NG.
From the results of the search, locate the plug-in and click on Add to Thunderbird.
Finally, follow the prompts to confirm your installation, and restart Thunderbird when prompted.

Step #3: Exporting Your IMAP Folders in MBOX

Locate the IMAP account on the left-hand pane of Thunderbird.
Right click on the folder you want to export (e.g. Inbox, Sent, or a label made by you).
Hover over ImportExportTools NG in the context menu.
Click on Export folder (MBOX) and choose As MBOX file (or the relevant option to include sub-folders if needed).
A file browser window will pop up, choose your desired destination folder on your PC’s hard drive and click on Select Folder.

Tip: When you export selected email messages using Thunderbird, your emails are compiled in a clean .mbox file at the location you specify. You can now archive your emails, create backups, or import them into other MBOX compatible client programs such as Apple Mail when using the .mbox file type. Or you can even convert mbox to pdf.

Limitations of Manual Approach

The procedure for downloading large mailboxes via IMAP and manually processing the files can take quite a long time.
You can lose or corrupt emails due to accidental deletion, sync issues, or even an incorrect configuration.
This method requires various third-party plugins and client configuration, which can be quite overwhelming for users with little technical knowledge.
This process is not able to be automated or scheduled, which means that emails have to be downloaded manually each time.
This method relies entirely on Mozilla Thunderbird and compatible plug-ins functioning correctly.

Export IMAP Emails to MBOX Using Professional Tool

MailsWare Email Migrator Toolkit is known as an ultimate and complete solution that can quickly migrate mailboxes to several prominent platforms without any data loss. There is effective batch migration mode in the toolkit which means users can transfer big email data files in bulk without size limitations and chances of losing file formats. The sophisticated custom filters and proxy server functions allow users to have the full control of their email migration and ensure security of their sensitive data either when moving certain folders or whole corporate servers. The easy and friendly user interface allows non-specialists to perform data transfer easily and very quickly.

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How to Export IMAP Emails to MBOX Format? [Stepwise]

Download, install and launch the MailsWare utility on your PC. Select IMAP Server option from the email source list.
Input your email account credentials, i.e. ID & Password along with IMAP Host & Port. Make sure that you have any additional security parameters such as Authentication Codes, App Passwords, etc. so as to authorize the login. In case you want to backup multiple email accounts from the same platform, select Use Batch Mode checkbox to input multiple credentials simultaneously. Click Login.
The tool will successfully fetch your email data that you can preview.
Select the items to be imported. Click on the drop-down button of Select Saving Options and select MBOX to export data into MBOX format on the hard drive of your PC. Set the Destination Path where it needs to be saved. Click Backup.
The software will start the export process and notify when the task gets completed successfully.Powerful Features of the Tool

Salient Features of the Tool

The tool does not hamper the integrity of emails during the process.
Preserves email metadata, body, formatting and other vital/essential attributes of the email contents.
It backs up your emails along with their attachments in their original format.
The tool works fast and eliminates all the complications faced by users during backup.
Allows you to backup selective email data using filter options or criteria such as, Sender, To, From, etc.
Enables user to schedule the backup process by setting the timestamps.
Provides multiple file-formats and cloud-based platforms for data backup and/or migration.
Besides hard drive, also enables backup to other useful storage media such as, USB, NAS Storage, etc.
Allows bulk export of your emails using the advanced & inbuilt Batch Mode feature.
Seamlessly compatible with both Windows & Mac powered PCs.

FAQ

Q: Is it feasible to transfer IMAP emails into MBOX format without the use of software tool?

Exporting capability through the default methods is unlikely. Therefore, you will either need an add-on, for instance – Thunderbird’s ImportExportTools NG – or you will need to choose expert third-party service like MailsWare which offers this functionality.

Q: What amount of time is required for an IMAP to MBOX conversion?

It really depends upon the speed of your Internet connection and the size of your total mailbox. Small folders will take minutes, whereas bulky email archives with lots of attachments may require several hours.

Q: Will the hierarchy of folders be saved during the transfer?

If you take advantage of products like Thunderbird with proper export configuration, your folder arrangement will be preserved. However, it is advisable to check whether the result of exporting this file into MBOX format is appropriate by checking it with an MBOX compatible email client.

Q: Is it possible to only transfer certain folders based on timestamp instead of the whole mailbox?

Manual methods in Thunderbird generally transfer the complete folder rather than the particular time-filtered parts. So if you need precise chronological filters, you need specialized automated programs.

Q: Is it okay to remove emails from the IMAP server after the transfer process?

It is only safe to delete the emails once you have confirmed that the exported file opens properly and has the required data in it. The ideal situation would be to have a local backup saved in a separate secure location.

Summary – Key Takeaways

When emails are placed in a nearby local storage facility or when passed to a proper desktop program like Thunderbird or Apple Mail, the emails are guaranteed security in case servers are lost and are accessible even when not connected to the Internet.
Mozilla Thunderbird needs to be downloaded, IMAP account to be set up, ImportExportTools NG plugin to be downloaded and applied, and folders need to be exported one by one as .mbox files.
Time-consuming for large numbers of emails since there are no automatic features, many problems might occur due to outages not controlled by an end-user.
The MailsWare toolkit simplifies the process and provides unlimited options when converting between IMAP and MBOX formats.
Application makes possible incremental backups, filtering emails by date and sender, and transferring dozens of accounts at the same time with no problem.