Users are required to change their source .mobx folder when Mail.app changes its folder to the new version. Apple updates the Mail.app folder version to a new one sometimes when they update the OS. For example, after updating from MacOS 10.15 to MacOS 11.0 the mail folders switched from 'V7' to 'V8'. So let's see how we can change our source folder to keep the archives running:

  1.  In Email Archiver click on ‘V7’ (under the folders title in the left hand side)
  2. Click remove (this will only remove the item from Email Archiver, none of the files Email Archiver has created will be touched)
  3. [OPTIONAL] Open Finder and navigate to the(PDF) save location you set in email archiver (this is usually in your ~/Documents folder)
  4. [OPTIONAL] rename the V7 folder to V8
  5. In Email Archiver click ‘Add Mailbox From Mail.app’ and select 'V8'.

If you do not do the [OPTIONAL] steps, Email Archiver will treat the newly added V8 folder as though it has never seen it before and archive every email (duplicating the contents of V7). You probably do want to do the optional steps.