Funnily you've kinda inverted the mailboxes purpose: your real inbox is called "quarantine", and your actual emails are in your "inbox". Sounds like you could use inbox as inbox and then "archive" when it passes validation.
Anyway if it works for you _and_ is simple to put in place and use (as you've shown), then kudos to you!
Anyway if it works for you _and_ is simple to put in place and use (as you've shown), then kudos to you!