Send email in java

Mailer.java

import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

import javax.mail.Address;
import javax.mail.Authenticator;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.PasswordAuthentication;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.AddressException;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;

public class Mailer {
  private Properties mailSettings;
	
  public Mailer() throws IOException {
    InputStream is = null;
    try {
    	is = this.getClass().getClassLoader().getResourceAsStream("mail.properties");
    	mailSettings = new Properties();
    	mailSettings.load(is);
    	mailSettings.put("mail.smtp.auth", "true");
    	mailSettings.put("mail.transport.protocol", "smtp");
    } finally {
      try {
        if(is != null) { is.close(); }
      } catch(IOException e) {}
    }
  }
	
  public void send(String content) throws AddressException, MessagingException {
    Session session = Session.getDefaultInstance(mailSettings, new SMTPAuthenticator());
    Message message = new MimeMessage(session);
    message.setFrom(new InternetAddress(mailSettings.getProperty("from")));
    message.addRecipients(Message.RecipientType.TO, getRecipients());
    message.setSubject("Test mail from java");
    message.setText("This is a test mail.");
    Transport.send(message);
  }
	
  private Address[] getRecipients() throws AddressException {
    String recipients = mailSettings.getProperty("to");
    String[] emails = recipients.split(",");
    Address[] emailAddress = new InternetAddress[emails.length];
    
    int index = 0;
    for(String email : emails) {
      emailAddress[index++] = new InternetAddress(email);
    }
    
    return emailAddress;
  }
	
  private class SMTPAuthenticator extends Authenticator {
    @Override
    protected PasswordAuthentication getPasswordAuthentication() {
      return new PasswordAuthentication(mailSettings.getProperty("username"), 
        mailSettings.getProperty("password"));
    }
  }
}