Sending mail using the @Configuration annotation

We shall demonstrate here how we can send mail using the Spring mail API.

1. First, we provide all the SMTP details in the .properties file and read it to the class file with the @Configuration annotation. The name of the class is MailConfiguration.

   mail.properties file contents are shown below:

   mail.protocol=smtp
   mail.host=localhost
   mail.port=25
   mail.smtp.auth=false
   mail.smtp.starttls.enable=false
   mail.from=me@localhost
   mail.username=
   mail.password=
   
   @Configuration
   @PropertySource("classpath:mail.properties")
   public class MailConfiguration {
     @Value("${mail.protocol}")
     private String protocol;
     @Value("${mail.host}")
     private String host;
     @Value("${mail.port}")
     private int port;
     @Value("${mail.smtp.auth}")
     private boolean auth;
     @Value("${mail.smtp.starttls.enable}")
     private boolean starttls;
     @Value("${mail.from}")
     private String from;
     @Value("${mail...