这将只显示您的电子邮件客户端(以及PayPal出于某些未知的原因)

 public void composeEmail() {

    Intent intent = new Intent(Intent.ACTION_SENDTO);
    intent.setData(Uri.parse("mailto:"));
    intent.putExtra(Intent.EXTRA_EMAIL, new String[]{"hi@example.com"});
    intent.putExtra(Intent.EXTRA_SUBJECT, "Subject");
    intent.putExtra(Intent.EXTRA_TEXT, "Body");
    try {
        startActivity(Intent.createChooser(intent, "Send mail..."));
    } catch (android.content.ActivityNotFoundException ex) {
        Toast.makeText(MainActivity.this, "There are no email clients installed.", Toast.LENGTH_SHORT).show();
    }
}

我很久以前就一直在用这个，看起来不错，没有非电子邮件应用程序显示。这是发送电子邮件意图的另一种方式:

Intent intent = new Intent(Intent.ACTION_SENDTO); // it's not ACTION_SEND
intent.putExtra(Intent.EXTRA_SUBJECT, "Subject of email");
intent.putExtra(Intent.EXTRA_TEXT, "Body of email");
intent.setData(Uri.parse("mailto:default@example.com")); // or just "mailto:" for blank
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK); // this will make such that when user returns to your app, your app is displayed, instead of the email app.
startActivity(intent);

简单，试试这个

 public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    buttonSend = (Button) findViewById(R.id.buttonSend);
    textTo = (EditText) findViewById(R.id.editTextTo);
    textSubject = (EditText) findViewById(R.id.editTextSubject);
    textMessage = (EditText) findViewById(R.id.editTextMessage);

    buttonSend.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {

            String to = textTo.getText().toString();
            String subject = textSubject.getText().toString();
            String message = textMessage.getText().toString();

            Intent email = new Intent(Intent.ACTION_SEND);
            email.putExtra(Intent.EXTRA_EMAIL, new String[] { to });
            // email.putExtra(Intent.EXTRA_CC, new String[]{ to});
            // email.putExtra(Intent.EXTRA_BCC, new String[]{to});
            email.putExtra(Intent.EXTRA_SUBJECT, subject);
            email.putExtra(Intent.EXTRA_TEXT, message);

            // need this to prompts email client only
            email.setType("message/rfc822");

            startActivity(Intent.createChooser(email, "Choose an Email client :"));

        }
    });
}

Kotlin版本，只显示电子邮件客户端(没有联系人等):

    with(Intent(Intent.ACTION_SEND)) {
        type = "message/rfc822"
        data = Uri.parse("mailto:")
        putExtra(Intent.EXTRA_EMAIL, arrayOf("user@example.com"))
        putExtra(Intent.EXTRA_SUBJECT,"YOUR SUBJECT")
        putExtra(Intent.EXTRA_TEXT, "YOUR BODY")
        try {
            startActivity(Intent.createChooser(this, "Send Email with"))
        } catch (ex: ActivityNotFoundException) {
            // No email clients found, might show Toast here
        }
    }

使用. settype ("message/rfc822")或ACTION_SEND的策略似乎也适用于非电子邮件客户端的应用程序，如Android Beam和蓝牙。

使用ACTION_SENDTO和mailto: URI似乎工作得很好，并且在开发人员文档中推荐使用。但是，如果你在官方模拟器上这样做，并且没有设置任何电子邮件帐户(或者没有任何邮件客户端)，你会得到以下错误:

不支持的操作 目前不支持该操作。

如下图所示:

结果是模拟器将意图解析为一个名为com.android.fallback的活动。Fallback，它显示上面的消息。显然这是故意的。

如果你想让你的应用在官方模拟器上也能正常运行，你可以在发送邮件之前检查一下:

private void sendEmail() {
    Intent intent = new Intent(Intent.ACTION_SENDTO)
        .setData(new Uri.Builder().scheme("mailto").build())
        .putExtra(Intent.EXTRA_EMAIL, new String[]{ "John Smith <johnsmith@yourdomain.com>" })
        .putExtra(Intent.EXTRA_SUBJECT, "Email subject")
        .putExtra(Intent.EXTRA_TEXT, "Email body")
    ;

    ComponentName emailApp = intent.resolveActivity(getPackageManager());
    ComponentName unsupportedAction = ComponentName.unflattenFromString("com.android.fallback/.Fallback");
    if (emailApp != null && !emailApp.equals(unsupportedAction))
        try {
            // Needed to customise the chooser dialog title since it might default to "Share with"
            // Note that the chooser will still be skipped if only one app is matched
            Intent chooser = Intent.createChooser(intent, "Send email with");
            startActivity(chooser);
            return;
        }
        catch (ActivityNotFoundException ignored) {
        }

    Toast
        .makeText(this, "Couldn't find an email app and account", Toast.LENGTH_LONG)
        .show();
}

在开发人员文档中找到更多信息。

发送电子邮件可以用intent完成，不需要配置。但这样就需要用户交互，布局也会受到一些限制。

在没有用户交互的情况下构建和发送更复杂的电子邮件需要构建自己的客户端。第一件事是用于电子邮件的Sun Java API不可用。我曾经成功地利用Apache Mime4j库来构建电子邮件。都是基于nilvec的文件。