private void sendMail(){  
Intent intent = new Intent(Intent.ACTION_SEND);
intent.setType("message/rfc822");
intent.putExtra(Intent.EXTRA_SUBJECT,"邮件标题");
intent.putExtra(Intent.EXTRA_TEXT, "邮件正文内容" + "\n"+"分享自-----");
startActivity(Intent.createChooser(intent,"选择发送E-mail的应用程序"));
}

如上。