How to Test Emails in Mandrill, Sendgrid, and Mailgun

In our previous post, we reviewed Sendgrid, Mandrill, and Mailgun - the most popular email sending services. “Test your emails before actually sending them”: each of them repeats this mantra, as does anyone who deals with email development. But do these services offer enough options for quality email testing? Let’s have a closer look at the checkpoints and see if there is a need for a special testing service.