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 :"));

        }
    });
}

import androidx.core.app.ShareCompat
import androidx.core.content.IntentCompat

ShareCompat.IntentBuilder(this)
                .setType("message/rfc822")
                .setEmailTo(arrayOf(email))
                .setStream(uri)
                .setSubject(subject)
                .setText(message + emailMessage)
                .startChooser()

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);
        }
    }
}

/**
 * Will start the chosen Email app
 *
 * @param context    current component context.
 * @param emails     Emails you would like to send to.
 * @param subject    The subject that will be used in the Email app.
 * @param forceGmail True - if you want to open Gmail app, False otherwise. If the Gmail
 *                   app is not installed on this device a chooser will be shown.
 */
public static void sendEmail(Context context, String[] emails, String subject, boolean forceGmail) {

    Intent i = new Intent(Intent.ACTION_SENDTO);
    i.setData(Uri.parse("mailto:"));
    i.putExtra(Intent.EXTRA_EMAIL, emails);
    i.putExtra(Intent.EXTRA_SUBJECT, subject);
    if (forceGmail && isPackageInstalled(context, "com.google.android.gm")) {
        i.setPackage("com.google.android.gm");
        i.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        context.startActivity(i);
    } else {
        try {
            context.startActivity(Intent.createChooser(i, "Send mail..."));
        } catch (ActivityNotFoundException e) {
            Toast.makeText(context, "No email app is installed on your device...", Toast.LENGTH_SHORT).show();
        }
    }
}

/**
 * Check if the given app is installed on this devuice.
 *
 * @param context     current component context.
 * @param packageName The package name you would like to check.
 * @return True if this package exist, otherwise False.
 */
public static boolean isPackageInstalled(@NonNull Context context, @NonNull String packageName) {
    PackageManager pm = context.getPackageManager();
    if (pm != null) {
        try {
            pm.getPackageInfo(packageName, 0);
            return true;
        } catch (PackageManager.NameNotFoundException e) {
            e.printStackTrace();
        }
    }
    return false;
}

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。

下面是在android设备中打开邮件应用程序并在编写邮件时自动填充To address和Subject的示例工作代码。

protected void sendEmail() {
    Intent intent = new Intent(Intent.ACTION_SENDTO);
    intent.setData(Uri.parse("mailto:feedback@gmail.com"));
    intent.putExtra(Intent.EXTRA_SUBJECT, "Feedback");
    if (intent.resolveActivity(getPackageManager()) != null) {
        startActivity(intent);
    }
}