[whpalmer4]

I don't think there is any method to take an action in a Mail rule based on the result of another action. However, it does seem like the OmniFocus script could be easily improved by adding the line starting with "+":

		tell application "OmniFocus"
			set AllowedSender to allowed mail senders
			if AllowedSender does not contain trimmedSender and AllowedSender does not contain theSender then
+				log "Received message from unauthorized sender " & trimmedSender & ", ignoring"
				return
			end if
		end tell

I change the Mail rule to put all of the messages in a separate folder rather than deleting them.