Petal::Mail processes a Petal XML template, and then turns the resulting XML into a text email which can be sent through sendmail or other. The XML has to follow a certain syntax which is defined in this documentation. Since Petal::Mail's is a subclass of Petal, its API is the same. Which means you need to read about Petal before you can use Petal::Mail. WWW: https://metacpan.org/release/Petal-Mail