How to export larger than 2.15GB mailbox (Mbox file) from the Apple Mail app?

There has been a lot of discussions on how to export larger than 2.15GB from the Apple Mail app. "Sinetempore" said to have found a way to save and then import (e.g. onto another laptop) larger than 2.15GB Mbox file. The method goes as follows:

1. Copy and save anywhere your Mbox file that can be found from Users/[User]/Library/Mail/V[*]/[*]/[youremailsfolder.mbox]

2. In Mail app select File/Import Mailboxes.../Apple Mail/Continue and then choose the Mbox you just saved.

3. Wait and then select only the first listed folder (possibly a lot of folders appear, unselect All by selecting the dot above, and then select only the first folder) > click Continue.

I tried this method of manual export/import and it works perfectly. No limits with file sizes.