Mail Archiver can export your emails into mbox format. Mail is very picky what it imports. Eml files work better than mbox files. Postbox only imports files with a special structure. Outlook doesn't import mbox or eml files at all.

But sometimes you need your archived emails back in your email client. That's what the "Upload to" menu item in the Email menu is for.

Even if you only archive from your email client you need to the one IMAP account in Mail Archiver.

In the Setup go to accounts and create an account:

If you don't know your account settings check out the blog article on how to archive from IMAP.

Make sure that the account logs in fine. You don't need to do anything else with the account like adding it to a plan. The account just needs to be there. Close the window.

Now we are going to upload the emails:

  1. Select some emails.
  2. Select Email -> Upload to -> Account 1.

That's it. Let the email client synchronise the account. The emails should show up in the mailbox they had in Mail Archiver. If you need them in another location you can drag them there.