How to Import MBOX into Gmail

Thomas

3 years ago

Users who migrate between mail systems face one major problem — format clash. If your data is stored as MBOX, Gmail will not allow you to import it directly. The process requires an intermediary — another mail client or third-party software. The guide covers three common ways to import MBOX to Gmail. If you need to download your entire mailbox, there is no simple workaround.

Getting Ready for Transfer

To move and convert the files for backup, you will need either MS Outlook or Mozilla Thunderbird. These systems will serve as intermediaries, as your Google account can be connected to either of them. You need to:

turn on the IMAP mode and
link your Gmail account to the desktop software

Turning on IMAP for the Gmail Account

There are two modes for synchronization — POP and IMAP. In the first case, the system does not preserve the mailbox structure or label information. Thus, you need to activate the other option to import MBOX files conveniently. Here is how.

After logging in to your Google mailbox, click on the gear icon next to your profile photo to access the settings.
Click See all Settings.
Open the Forwarding and POP/IMAP tab and activate the latter if it has not been enabled before.
Click Save Changes.

Adding Gmail in Outlook

To be able to import MBOX to Gmail, you can use the Windows client as an intermediary. First, connect it to your mail account. There are just four steps to take.

Go to the File section to access the settings for your account.
Proceed to Account Settings… at the top of the menu.
On the Email tab of the new window, choose New….
Enter your Gmail credentials and connect the account.

Adding Gmail in Thunderbird

Alternatively, users of Mozilla can achieve the goal through the app. Follow the steps below to connect your Gmail account. This is not as easy as with Outlook, but the method will also allow you to import MBOX into Gmail.

Open the ‘Tools’ menu to access the settings section for your account.
Choose ‘Create a new account’.
Enter your Google mail credentials and name. The system will then try to configure the account, but this will likely fail.
Choose manual configuration:

‘imap.gmail.com’ with ‘Port: 993’ and ‘SSL: SSL/TLS’ for incoming server, normal password as verification method;
‘smtp.gmail.com’ with ‘Port: 465’, the rest of the settings are identical;
username — your Gmail address.

How to Import MBOX into Gmail via Outlook Converter

If your Gmail account is linked to Outlook, the transfer is a piece of cake. All you need is a reliable tool to convert the mail, such as Mbox to Outlook Transfer. The system will transform your data into PST — the proprietary format for all versions of the legendary app. Then, you will be able to open the file in the mail client and move the items easily, so they are synced with Gmail.

Mbox to Outlook Transfer tool

* - The unregistered version converts a limited number of messages

The system has two modes — it can convert and export directly to your profile or a standalone file. The first method is not officially supported by Gmail but works for some users. If the system fails to restore the folders after you import MBOX files, create a separate file and open it in Outlook manually. Here is how.

Launch Outlook and open the [media]File[/media] section.
Launch the wizard for import/export through [media]Open & Export[/media].
Choose to import from another file or program.
As we will be using a PST file, choose [media]Outlook Data File (.pst)[/media] from the list to convert the mail.
Browse to the location of the PST file created through conversion.
Decide what to do with duplicates (we recommend you replace them with imported items).
Specify the source folder to import the MBOX file.
If you have several accounts linked with Outlook, choose the right ID in [media]Import items into the same folder in[/media] (this should not be your Gmail folder).
Click [media]Finish[/media].
Drag and drop the MBOX file items to your Google folder.

That’s all. Now, the contents of your MBOX file should appear in the desired location. The system will sync the contents automatically, so you can view them from any device. Creating the PST format using the utility is simple, and you can run the operation as many times as you want — i.e., feed multiple MBOX files into your Gmail account.

Importing MBOX File to Gmail by Changing the File Extension

If you have one or two messages, you can simply change the extension to EML and drag them into your Gmail account. This is a quick procedure. By default, the file will be downloaded as ZIP, and you will need to extract the data. Here is the first stage of this manual way to move Mbox to Gmail:

Download your MBOX file from the source app.
Extract the contents to a location on your PC you find appropriate.
Right-click on the file to open the menu with the necessary options.
Choose to rename to be able to change the type.
Replace the .mbox extension with .eml
Confirm the choice.

Now, instead of an MBOX file, you have an EML file that is perfectly compatible with Outlook. All you need to do is move it into the app. Follow these steps:

Drag and drop the file under the appropriate label.
Open it by double-clicking on it.
Confirm with ‘Yes’ to import MBOX into Gmail.
Click ‘Open’ to make the message visible.

As you can see, this is a relatively straightforward procedure. It works like a charm for one message, but batch processing (import of multiple emails) is a different story. The MBOX file may contain dozens or hundreds of messages. If you import them this way, they will all appear under the same label and message. This is, obviously, inconvenient.

Upload and Open an MBOX File via Thunderbird

This mail client is a popular alternative to Outlook. It is free and open-source. The system will recognize your MBOX file, so you can also use it as another workaround. However, the default functionality is insufficient for the task — you will need to install an add-on called ImportExportTools.

Link your Gmail account to Thunderbird (see the steps above).
Right-click on the left-hand pane to unfold the menu with the ImportExportTools option. Place your pointer on it to open another menu.
Choose ‘Import MBOX file’ to summon the wizard.
As you know where your file is stored, choose to “Import directly one or more mbox files”.
Browse to the location of the MBOX data and click ‘Open’.
After import, move the emails to your Gmail Account by dragging and dropping between folders.

Note: the system will import MBOX into a new folder in Thunderbird. Its name will be the same as the original file name, but you can change it if necessary. If the exported data does not appear, try restarting the mail app.

How to Install ImportExportTools Add-on

Here is how to add the add-on for MBOX files for your Thunderbird. This is a matter of a few clicks. Remember to restart the app after completion and link your Google account (see above)

Click on the options icon (three vertical lines) in the upper right corner to open the menu.
Choose the ‘Add-ons’ option.
Choose ‘ImportExportTools NG’ from the featured list.
Click on the green button with a ‘+’ sign to add it.
Choose to install now.

Conclusion: Backup and Restore Your Mail

Unfortunately for users, it is impossible to directly import the data. If you want to open MBOX files from your Google mail account, you need an intermediary tool — a converter or a mail client. In the case of Thunderbird, a special add-on is required.