Your email messages are some of the most important files on your Mac, so they belong at the top of the list in your new backup regimen. Fortunately, you don’t need extra software to export, back up, and import your mail. Everything you need to do the job is in Mail, Outlook, or Thunderbird—and this guide. Just connect an external drive to your Mac and get started.
In the sidebar, select each mailbox, Smart Mailbox, or folder you want to back up. Select Mailbox > Export Mailbox, and pick your external drive as the export’s destination. Click Choose to export.
Mail’s all-purpose gear icon is another way to export mailboxes.
Launch Mail on your new Mac, then after setting up an account, choose Import > Import Mailboxes. Set Apple Mail as the application you’ll be importing from, then select your exported mailboxes and click Choose. Confirm the import in the next window, then click Continue. Your imported mail will appear in the Import folder in Mail’s sidebar.
Quit Thunderbird, then switch to the Finder. Holding the Option key, select Go > Library, then navigate to Library > Thunderbird > Profiles. Inside, you’ll find your profile folder, named xxxxxxxx.default (where “xxxxxxxx” is a unique string of characters). Drag it to your external drive.
Backing up Thunderbird data is all about your profile folder.
Launch and quit Thunderbird on your new Mac, ignoring the prompt to create a new account. Navigate to Library > Thunderbird > Profiles. Select the files in the new profile folder and drag them to the Trash, but don’t delete the new profile folder itself. Select the files in your original profile folder, then drag them into the empty profile folder on your Mac. Relaunch Thunderbird to find your old mail and accounts just as you left them.
Select File > Export, and in the resulting window choose to export an Outlook For Mac Data File. Then select Items Of The Following Types and check mail (and any other data type) to back up. Choose whether or not to delete your data after export, then select your external drive in the Save window to export the archive.
Imported mail is easy to find in Outlook 2011’s sidebar.
Launch Outlook on your new Mac, select File > Import, then choose to import an Outlook Data File. Choose Outlook For Mac Data File in the next window, then choose the file on your external drive and click Import. Your old mail will appear in the Archived Mail folder in Outlook’s sidebar.
