Component Breakdown

Swift Mailer is made up of many classes. Each of these classes can be grouped into a general "component" group which describes the task it is designed to perform.

We'll take a brief look at the components which form Swift Mailer in this section of the book.

1. The Mailer
   The mailer class, Swift_Mailer is the central class in the library where all of the other components meet one another. Swift_Mailer acts as a sort of message dispatcher, communicating with the underlying Transport to deliver your Message to all intended recipients.
2. Transports
   Transports are the classes in Swift Mailer that are responsible for communicating with a service in order to deliver a Message. There are several types of Transport in Swift Mailer, all of which implement the Swift_Transport interface and offer underlying start(), stop() and send() methods.
3. MIME Entities
   Everything that forms part of a Message is called a MIME Entity. All MIME entities in Swift Mailer share a common set of features. There are various types of MIME entity that serve different purposes such as Attachments and MIME parts.
4. Encoders
   Encoders are used to transform the content of Messages generated in Swift Mailer into a format that is safe to send across the internet and that conforms to RFC specifications.
5. Plugins
   Plugins exist to extend, or modify the behaviour of Swift Mailer. They respond to Events that are fired within the Transports during sending.