Applescript to auto save mail attachment in Apple Mail

-- Tested on macOS 10.13.6

use AppleScript version "2.4"
use scripting additions

using terms from application "Mail"
    on perform mail action with messages messageList in mailboxes mbox for rule aRule

        --  Save on DesktopPath
        set desktopPath to (path to desktop) as string

        tell application "Mail"
            set selectedMessages to the selection
            repeat with aMessage in selectedMessages
                repeat with anAttachment in mail attachments of aMessage
                    set attachmentName to name of anAttachment
                    save anAttachment in file (desktopPath & attachmentName)

                end repeat
            end repeat
        end tell

    end perform mail action with messages
end using terms from