Since there appears to be no way to automate the saving of mail attachments in the Apple Mail app (no way that actually works), I'm looking for an alternative mail app that will allow you to do this. I've tried Applescript triggered by a rule to do this, but Apple has broken something inside Mail that makes it impossible to do this on El Capitan (works if I trigger the rule manually, but won't work automatically - long story). Anyway, my hack-around is to use another mail app for this one purpose with a special mail account set up for this one purpose. If that won't work, the other is to traverse through the Mail app's tangled mailbox directory structure looking for newly downloaded attachments.
