i have just installed SpamSieve, and it seemed to be going alright until i accidentally tagged an email wrongly and then found that to undo this i was meant to go to the SPAM folder and could then undo my mistake
but the SPAM folder is totally empty, no emails in it at all, let alone any coloured emails
so i assume that this is not the way the app is supposed to work
There is no feature in SpamSieve or Mail to automatically delete the messages in the Spam mailbox. So if the messages aren’t there, that could indicate that Mail’s database needs to be rebuilt.
I suppose the other possibility is if you’ve changed the settings so that the trained messages go to a different mailbox.