Intent emailIntent = new Intent(Intent.ACTION_SENDTO, Uri.fromParts(
            "mailto","ebgsoldier@gmail.com", null));
    emailIntent.putExtra(Intent.EXTRA_SUBJECT, "Forgot Password");
    emailIntent.putExtra(Intent.EXTRA_TEXT, "this is a text ");
    startActivity(Intent.createChooser(emailIntent, "Send email..."));

我使用这段代码通过直接启动默认的邮件应用程序撰写部分来发送邮件。

    Intent i = new Intent(Intent.ACTION_SENDTO);
    i.setType("message/rfc822"); 
    i.setData(Uri.parse("mailto:"));
    i.putExtra(Intent.EXTRA_EMAIL  , new String[]{"test@gmail.com"});
    i.putExtra(Intent.EXTRA_SUBJECT, "Subject");
    i.putExtra(Intent.EXTRA_TEXT   , "body of email");
    try {
        startActivity(Intent.createChooser(i, "Send mail..."));
    } catch (android.content.ActivityNotFoundException ex) {
        Toast.makeText(this, "There are no email clients installed.", Toast.LENGTH_SHORT).show();
    }

筛选“真正的”电子邮件应用程序在今天仍然是一个问题。正如上面许多人提到的，现在其他应用程序也报告支持mime类型的“message/rfc822”。因此，这种mime类型不再适合用于真正的电子邮件应用程序的过滤。

如果你想发送一个简单的文本邮件，使用ACTION_SENDTO意图动作和适当的数据类型就足够了，如下所示:

Intent intent = new Intent(Intent.ACTION_SENDTO);
intent.setData(Uri.parse("mailto:"));
intent.putExtra(Intent.EXTRA_EMAIL, recipients);
intent.putExtra(Intent.EXTRA_SUBJECT, subject);
intent.putExtra(Intent.EXTRA_TEXT, text);
Intent chooser = Intent.createChooser(intent, "Send Mail");
context.startActivity(chooser);

这将过滤所有支持“mailto”协议的应用程序，这更适合发送电子邮件。

但不幸的是，如果你想发送带有(多个)附件的邮件，事情就变得复杂了。ACTION_SENDTO动作不支持EXTRA_STREAM额外的意图。如果你想使用它，你必须使用ACTION_SEND_MULTIPLE动作，它不能与数据类型Uri.parse("mailto:")一起工作。

目前我找到了一个解决方案，具体步骤如下:

声明你的应用程序想要查询设备上支持mailto协议的应用程序(对Android 11以来的所有应用程序都很重要) 实际上查询所有支持mailto协议的应用程序 对于每个支持应用:构建你真正想要启动的意图，针对那个单一的应用 构建App选择器并启动它

这是它在代码中的样子:

添加到AndroidManifest:

<queries>
    <intent>
        <action android:name="android.intent.action.SENDTO" />
        <data android:scheme="mailto" />
    </intent>
</queries>

这是Java代码:

/* Query all Apps that support the 'mailto' protocol */
PackageManager pm = context.getPackageManager();
Intent emailCheckerIntent = new Intent(Intent.ACTION_SENDTO, Uri.parse("mailto:"));
List<ResolveInfo> emailApps = pm.queryIntentActivities(emailCheckerIntent, PackageManager.MATCH_DEFAULT_ONLY);

/* For each supporting App: Build an intent with the desired values */
List<Intent> intentList = new ArrayList<>();
for (ResolveInfo resolveInfo : emailApps) {
    String packageName = resolveInfo.activityInfo.packageName;
    Intent intent = new Intent(Intent.ACTION_SEND_MULTIPLE);
    intent.setPackage(packageName);
    intent.setComponent(new ComponentName(packageName, resolveInfo.activityInfo.name));
    intent.putExtra(Intent.EXTRA_EMAIL, recipients);
    intent.putExtra(Intent.EXTRA_SUBJECT, subject);
    intent.putExtra(Intent.EXTRA_TEXT, text);
    intent.putExtra(Intent.EXTRA_STREAM, attachmentUris);
    intent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION); //IMPORTANT to give the E-Mail App access to your attached files
                
    intentList.add(intent);
}

/* Create a chooser consisting of the queried apps only */
Intent chooser = Intent.createChooser(intentList.remove(intentList.size() - 1), "Send Mail");
Intent[] extraIntents = intentList.toArray(new Intent[0]);
chooser.putExtra(Intent.EXTRA_INITIAL_INTENTS, extraIntents);
context.startActivity(chooser);

注意:如果itentList只有一个项目，Android会自动跳过选择器并自动运行唯一的应用程序。

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 :"));

        }
    });
}

这个函数首先直接意图gmail发送电子邮件，如果gmail没有找到，然后提升意图选择器。我在许多商业应用程序中使用了这个功能，它工作得很好。希望对你有所帮助:

public static void sentEmail(Context mContext, String[] addresses, String subject, String body) {

    try {
        Intent sendIntentGmail = new Intent(Intent.ACTION_VIEW);
        sendIntentGmail.setType("plain/text");
        sendIntentGmail.setData(Uri.parse(TextUtils.join(",", addresses)));
        sendIntentGmail.setClassName("com.google.android.gm", "com.google.android.gm.ComposeActivityGmail");
        sendIntentGmail.putExtra(Intent.EXTRA_EMAIL, addresses);
        if (subject != null) sendIntentGmail.putExtra(Intent.EXTRA_SUBJECT, subject);
        if (body != null) sendIntentGmail.putExtra(Intent.EXTRA_TEXT, body);
        mContext.startActivity(sendIntentGmail);
    } catch (Exception e) {
        //When Gmail App is not installed or disable
        Intent sendIntentIfGmailFail = new Intent(Intent.ACTION_SEND);
        sendIntentIfGmailFail.setType("*/*");
        sendIntentIfGmailFail.putExtra(Intent.EXTRA_EMAIL, addresses);
        if (subject != null) sendIntentIfGmailFail.putExtra(Intent.EXTRA_SUBJECT, subject);
        if (body != null) sendIntentIfGmailFail.putExtra(Intent.EXTRA_TEXT, body);
        if (sendIntentIfGmailFail.resolveActivity(mContext.getPackageManager()) != null) {
            mContext.startActivity(sendIntentIfGmailFail);
        }
    }
}

其他解决方案可以是

Intent emailIntent = new Intent(android.content.Intent.ACTION_SEND);
emailIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
emailIntent.setType("plain/text");
emailIntent.setClassName("com.google.android.gm", "com.google.android.gm.ComposeActivityGmail");
emailIntent.putExtra(android.content.Intent.EXTRA_EMAIL, new String[]{"someone@gmail.com"});
emailIntent.putExtra(android.content.Intent.EXTRA_SUBJECT, "Yo");
emailIntent.putExtra(android.content.Intent.EXTRA_TEXT, "Hi");
startActivity(emailIntent);

假设大多数android设备已经安装了GMail应用程序。