To import the 'On my mac' mailboxes from the Apple Mail app, please follow the steps below:
- Make a local account by going to ‘Preferences > Accounts > +sign > Add Local Account.
- Go to ‘Preferences > Accounts > [Local Account] > and choose Load message.
- In the finder press, Command + Shift + G and enter
- Choose V4 and the subsequent path.
Please note the 'subsequent path' referred here will vary from user to user and you will have to figure out which folder is the correct one to import.
Please contact support if you encounter any difficulties and we will be glad to help you out.