1. Put Notification of Payment Received in the subject line.
2. Don't put anything in the subject that is designed to trick me into opening it by pretending to be something that it is not.
Any one of the above will trigger an instant unsubscribe by me.
If you want me to click through anything in your message then you need to tell me what it is I will find when I do so. I have no time to mess about with guessing games.
Sorry for the rant but I am getting very annoyed by these emails and I will no longer tolerate them.