I’m a long-time user of SpamSieve and while browsing your website, found the application scripts. I’d like to use the two message up/down scripts for Apple Mail, but (hoping not to sound like too big an idiot) don’t know where to install them. I’ve checked inside Library Scripts folders (both universal and user) and can’t find a folder labeled “Mail.”
They should be installed in the folder ~/Library/Scripts/Applications/Mail/. You may need to create any or all of those folders within your user Library folder.