I would like to be able to search them and also import new emails (manually, I'm not going to connect to IMAP or anything else). It would need to ignore duplicated e-mails e.g. re-import a Google Takeout .mbox without creating complete chaos.
- me@example.com -- inbox -- sent -- folder1 -- folder2
- the-other-me@example.com -- inbox -- sent -- thingsishouldnthavesent