Use scripts as rule actions in Mail on Mac
You can attach an AppleScript script to a Mail rule. For example, you could have an incoming message trigger a script that copies information from the message and pastes it into a database that works with Script Editor.
In the Mail app on your Mac, choose Mail > Settings, then click Rules.
Select an existing rule, then click Edit, or click Add Rule to create a rule.
Click the “Perform the following actions” pop-up menu, then choose Run AppleScript.
From the pop-up menu, choose a script located in ~/Library/Application Scripts/com.apple.mail, or choose “Open in Finder” to open the folder so you can copy a script into it.
If you later move or rename the script, your rule will not work.
Click OK to save the rule.
If you use iCloud Drive, your rules are available on your other Mac computers that have iCloud Drive turned on and Mail selected in iCloud Drive options. Scripts attached to rules aren’t available. See Use iCloud Drive to store documents.