NOTE: This is mac only.
- Go to Finder.
- Press CMD+SHIFT+G.
- Type
~/Library/Application Scripts/com.apple.mail. - Open
saveByRule.scptand changetheFolderto where you'd like emails to be saved. - Copy and Paste
saveByRule.scptinto~/Library/Application Scripts/com.apple.mail. - Go to Mail>Preferences>Rules>Add Rule.