Yeah ... I was confused about this until I re-read the latest help. I now understand the trap Fastmail is worried we might get into if we mark the Spam folder as learn-as-spam. So they now don't learn messages as spam unless you do one of these things:
- Mark an undesired message in your Inbox (or some other normal folder) which evaded the spam filer as spam. I believe this immediately marks it as spam in the database.
- Permanently delete messages from the Spam folder. Fastmail is assuming that we will look at the Spam folder to verify there aren't any ham (non-spam) in there before we delete the messages. I believe that the auto-purge folder property will do this also.
- All of the permanently deleted messages from the Spam folder are learned as spam. So it's very important to not delete any non-spam messages which are accidentally in that folder! You need to mark ham (in the Spam folder) as Not Spam so they are learned correctly.
Bill