How to know which button a person clicked in CF7 PayPal?

If you have two buttons on your site “Pay via paypal” and “Send form without payment.” you not initially know in the mail what button the user has clicked. So you receive the same letter on both mails. So how do you understand from it which button a person clicked: does he want to pay via phone or has he already paid via PayPal?

Sometimes a letter from PayPal arrives only after an hour, and it’s not always possible to enter the admin area on the site. It is possible to make a difference in sending forms, depending on the clicks of different buttons, when you use the following tag in your mail settings:

[paypal_clicked]

It return “yes” if PayPal button was clicked and “no” if general submit button was clicked.