The Laravel News site has a post that gives you a quick introduction to MailThief, a library created by the developers at Tighten Co. to make mail testing simpler.

MailThief is a new package by Tighten Co. that provides a fake mailer for your Laravel application. This makes it easy to test email without actually sending any.

They include a simple example of a script that sends an email on user registration using Laravel's own Mail library. They also include a test for the registration action showing how MailThief can be used to "hijack" the mailer and make it simpler to get information about the mail being sent. You can find out more about the tool and what prompted it in this video from Adam Wathan.