Aquí está mi código que es capaz de enviar un correo electrónico con éxito

package com.send.email;    

import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends Activity {

Button send;

EditText address, subject, emailtext;
/** Called when the activity is first created. */

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

send = (Button) findViewById(R.id.emailsendbutton);

address = (EditText) findViewById(R.id.emailaddress);

 subject = (EditText) findViewById(R.id.emailsubject);

 emailtext = (EditText) findViewById(R.id.emailtext);

send.setOnClickListener(new OnClickListener() {

public void onClick(View v) {

// TODO Auto-generated method stub


final Intent emailIntent = new Intent(android.content.Intent.ACTION_SEND);

emailIntent.setType("image/png");

emailIntent.putExtra(android.content.Intent.EXTRA_EMAIL, new String[] { address.getText().toString() });

emailIntent.putExtra(android.content.Intent.EXTRA_SUBJECT, subject.getText());

emailIntent.putExtra(android.content.Intent.EXTRA_TEXT, emailtext.getText());

MainActivity.this.startActivity(Intent.createChooser(emailIntent,"Send mail..."));

}

});
}


@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data)
{

if(requestCode==1)
{
   if(requestCode==1 && resultCode==Activity.RESULT_OK)    
   {
       Toast.makeText(this, "Mail sent.", Toast.LENGTH_SHORT).show();


   }
   else if (requestCode==1 && resultCode==Activity.RESULT_CANCELED)
   {
       Toast.makeText(this, "Mail canceled.", Toast.LENGTH_SHORT).show();


   }
   else 
   {
       Toast.makeText(this, "Plz try again.", Toast.LENGTH_SHORT).show();

   }

}   
}
}

Quiero recuperar algo de información para comprobar si el correo electrónico se ha enviado correctamente o no. Siempre imprime el mensaje "enviar correo electrónico" y abre el cliente de correo electrónico incorporado y envía el correo electrónico.