Question

Im tring to send a simple email with this code using google app engine.
But nothing happens, is there something i have to configure in order to use the mail api?
This runs on localhost.
I am using gmail as mail host.

   String host = "smtp.google.com";
String to = "[e-mail]";
String from = "[e-mail]";
String subject = "this is a test";
String messageText = "test";
boolean sessionDebug = false;
// Create some properties and get the default Session.
Properties props = System.getProperties();
props.put("mail.host", host);
props.put("mail.transport.protocol", "smtp");
Session mailSession = Session.getDefaultInstance(props, null);

// Set debug on the Session
// Passing false will not echo debug info, and passing True will.

mailSession.setDebug(sessionDebug);

// Instantiate a new MimeMessage and fill it with the 
// required information.

Message msg = new MimeMessage(mailSession);
msg.setFrom(new InternetAddress(from));
InternetAddress[] address = { new InternetAddress(to) };
msg.setRecipients(Message.RecipientType.TO, address);
msg.setSubject(subject);
msg.setSentDate(new Date());
msg.setText(messageText);

// Hand the message to the default transport service
// for delivery.

Transport.send(msg);

Answer 1

When running the AppEngine development server locally, anything sent via the Mail service will not actually be sent – it will just be logged to the console

See here

When an application running in the development server calls the Mail service to send an email message, the message is printed to the log. The Java development server does not send the email message.

In addition, the from address must be (from here)

• The email of an app administrator
• The email of the currently logged in user who signed in using a Google Account
• A valid email receiving address from the app