I wrote the first post with this same issue in 2017... today, still with 10.14.3 I have the same problem: I am not able to export .mbox file larger than 2.15Gb. My Inbox is 2.9Gb, when I export it, the .mbox file size is always 2.15Gb!!! And if I import this 2.15Gb file, hundreds e-mails are missing from my original Inbox.
Unbelievable!
Anybody exporting his mailbox and getting this issue?
Make some mailboxes in your incoming mailbox. It’s much more easy to work with a well organised incoming mailbox.
Now you can export each of the sub-mailboxes
There is an alternate solution for this issue, a third party app called mail backup x, install that app on your Mac, add apple mail for backup. Once backup completed you can export to any format you need from the Retrieve / Export Data option from the dashboard. Also, the app will automatically back up every single email as soon as you received it in your inbox. Hope it will resolve your issue.
This may be a bug, but how come you have such a big InBox?
You know you can create as many mailboxes as you like, right? If baffles me how one leaves thousands of messages clogging the inbox and not organize them into mailboxes. Imagine a “real” mailbox like that?!
Export Mbox limited to 2.15Gb
