Finally, after a couple of years work, PHPMailer 6.0 has been released!
This is a major update that breaks backwards compatibility. For information about what's changed, refer to the changelog and README files.
The most important changes are that PHPMailer now defines a namespace (PHPMailer\PHPMailer), and requires a minimum of PHP 5.5. To find out more about how to upgrade, read the upgrade guide.