すべてのクラス
HtmlMailMessage
IntlJavaMailSender
IntlJavaMailSenderImpl
IntlMimeMessageHelper
MultipartJavaMailSender
MultipartJavaMailSenderImpl
MultipartMailMessage
PlainMailMessage
VelocityJavaMailSender
VelocityJavaMailSenderImpl
VelocityMailMessage
VelocityMailerSupport