How to get information about e-mails in Mail.app

If a user is reading e-mails in Mail.app and closes this appli开发者_如何学运维cation and opens my application. I want to show the information about the mail read by the user. Is there some way to get information about the email (in Mail.app), so that I use it in my application.

There is no way of reading the user's email.