# Mailer ### Installation ```shell composer require sonsofphp/mailer-contract ``` ### Definitions * **Message** - The email message that will be sent. * **Mailer** - Primary API used to send *messages*. * **Transport** - Transports are what will actually send the message. This could be SMTP, Null, SendGrid, Amazon SES, or anything like that. * **Middleware** - Before the message is sent to the transport to be sent, various middlewares have the ability to modify the message. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.sonsofphp.com/contracts/mailer.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.