Use Thunderbird to Migrate Your NCSU Gmail to Another Gmail Account


Restoring emails from a Google Takeout export back into Gmail can be done, but it requires the use of third-party applications to import the archived MBOX file back into another Gmail account. Google does not provide any direct mechanism to support this function.

It's important that you read through and understand all the steps involved in this process before you begin. You must set up Thunderbird, install the ImportExportTools add-on, import the emails, and copy the imported emails, as described below.

Set Up Thunderbird

First, you must set up your personal Gmail account with Thunderbird.

  1. Download and install the Thunderbird mail application.
  2. Launch Thunderbird and create a new account with your existing personal Gmail address.
  3. Enter your name, Gmail address, and Gmail password. Select Continue.
  4. Be sure that IMAP is selected and select Done.
  5. Sign into your Gmail account to authorize Thunderbird's access to your email. You should now see your Gmail account under All Folders, and you can open it to see all of your emails.

Install the ImportExportTools NG Add-on for Thunderbird

After Thunderbird is set up, you must install the ImportExportTools NG add-on.

  1. In Thunderbird, select the three horizontal lines to the right of the search bar.
  2. Select Add-ons.
  3. Search for import export tools.
  4. Select the link at the bottom to see all of the results.
  5. Hover over the ImportExportTools NG add-on, which should be first in the list, and select Add to Thunderbird.
  6. Select Install Now.
  7. Restart Thunderbird.

Import the Emails from the MBOX File

After the ImportExportTools add-on is installed, you will need to import the emails from the MBOX file downloaded from Google Takeout into a local folder. Please note that Thunderbird has a 4GB mailbox size limitation, so you may run into issues if you have more than 4GB of emails.

  1. In Thunderbird, right-click Local Folders and then select ImportExportTools NG - Import mbox file.
  2. Choose all mbox Files from directory and select OK.
  3. Locate the folder where you've saved the MBOX file that you want to import. Select the MBOX file and select Open.
  4. Be patient as all emails from the MBOX files will begin importing. This process may take a while.

Copy the Imported Emails into Your Gmail Account

Before copying the imported emails into your personal Gmail account, please make sure that it has the storage space to accept the files. Please note that it is best to import small amounts of data at a time, considering that there are restrictions on how much data you can upload via this method. Going over the limits can cause your account to be suspended for 1–24 hours.

  1. In Thunderbird, select Local Folders in the navigation pane on the left. Select the folder that has the name of the label that you want to import into Gmail.
  2. Drag and drop the emails or folders from the local folder to your personal Gmail account that was previously set up in Thunderbird. You can copy entire folders or individual messages.
  3. Be patient. The IMAP connection is limited by Google and it may take time to upload all of the data into your Google account. Thunderbird will need to remain open and connected to the internet to complete the upload.