How to test if PHP mail() has successfully delivered mail

Question

How can I test if mail() has successfully delivered mail?

Answer 1

The mail() function alone just notifies you that the "email" you have set up is legit and will be send my your email server.

You must check separately for the email address to be legit. A good article can be found here

If these two methods do not work for you well, you can use some "spam" approach using images and your server's log files.