Swiftmailer is not maintained anymore. Use Symfony Mailer instead. Read more on Symfony's blog. Using Swift Mailer for Japanese Emails To send emails in Japanese, you need to tweak the default configuration. Call the Swift::init() method with the following code as early as possible in your code: 1 2 3 4 5 6 7 8 9 Swift::init(function () { Swift_DependencyContainer::getInstance() ->register('mime.q