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.
Generally speaking you will not need to interact with the Encoders in Swift Mailer – the correct settings will be handled by the library itself. However they are probably worth a brief mention in the event that you do want to play with them.
Both the Headers and the body of all MIME entities (including the Message itself) use Encoders to ensure the data they contain can be sent over the internet without becoming corrupted or misinterpreted.
There are two types of Encoder: Base64 and Quoted-Printable.