I have found Email import / archive, but the question not answered (the thread moved on to automation of this).
There is a section in the manual entitled “Import vs. Archive Mailbox” on page 38, but it also does not describe the difference. It implies that “archive” is for entire mailboxes (all folders), whereas “import” is for selected folders in the mailbox.
However, when I select an individual folder in a mailbox (after Menu: Import/Email command), both the icon buttons “Import” and “Archive Mailbox” are active. I would expect, based on the manual, that Archive would only be active when selecting root mailbox folder (entire mailbox), and visa versa.
Also, based on my testing, it appears if a mail item is deleted in the mailbox, that deletion does not synch through to the copy stored in DEVONthink’s db? Is this correct.