SpamSieve

Pros:

• It exists?

Cons:

• Super hard to set up
• Considering the difficulty to make it work, it is likely you will do some kind of mistake you will spend hours (or more) to clean

• How to use it with SaneBox
• How to use it with an iOS device (or any smartphone or tablet):
  • Step 1
  • With Apple Mail, step 2
  • Script