适用于所有android版本:

String[] to = {"email@server.com"};
Uri uri = Uri.parse("mailto:email@server.com")
  .buildUpon()
  .appendQueryParameter("subject", "subject")
  .appendQueryParameter("body", "body")
  .build();
Intent emailIntent = new Intent(ACTION_SENDTO, uri);
emailIntent.putExtra(EXTRA_EMAIL, TO);
startActivity(Intent.createChooser(emailIntent, "Send mail..."));

更新到Android 10，现在使用Kotlin…

fun Context.sendEmail(
  address: String?,
  subject: String?,
  body: String?,
) {
  val recipients = arrayOf(address)
  val uri = address.toUri()
    .buildUpon()
    .appendQueryParameter("subject", subject)
    .appendQueryParameter("body", body)
    .build()
  val emailIntent = Intent(ACTION_SENDTO, uri).apply {
    setData("mailto:$address".toUri());
    putExtra(EXTRA_SUBJECT, subject);
    putExtra(EXTRA_TEXT, body);
    putExtra(EXTRA_EMAIL, recipients)
  }
  val pickerTitle = getString(R.string.some_title)
  ContextCompat.startActivity(this, Intent.createChooser(emailIntent, pickerTitle, null)
}

.．.在更新到API 30之后，代码没有填充电子邮件客户端的主题和主体(例如Gmail)。但我在这里找到了答案:

fun Context.sendEmail(
  address: String?,
  subject: String?,
  body: String?,
) {
  val selectorIntent = Intent(ACTION_SENDTO)
    .setData("mailto:$address".toUri())
  val emailIntent = Intent(ACTION_SEND).apply {
    putExtra(EXTRA_EMAIL, arrayOf(address))
    putExtra(EXTRA_SUBJECT, subject)
    putExtra(EXTRA_TEXT, body)
    selector = selectorIntent
  }
  startActivity(Intent.createChooser(emailIntent, getString(R.string.send_email))) 

}

这就是我使用的方法，对我来说很有效:

//variables
String subject = "Whatever subject you want";
String body = "Whatever text you want to put in the body";
String intentType = "text/html";
String mailToParse = "mailto:";

//start Intent
Intent variableName = new Intent(Intent.ACTION_SENDTO);
variableName.setType(intentType);
variableName.setData(Uri.parse(mailToParse));
variableName.putExtra(Intent.EXTRA_SUBJECT, subject);
variableName.putExtra(Intent.EXTRA_TEXT, body);

startActivity(variableName);

这也可以让用户选择他们喜欢的电子邮件应用程序。唯一不允许你做的是设置收件人的电子邮件地址。

与Kotlin，工作与Gmail:

val i = Intent(Intent.ACTION_SENDTO).apply {
    type = "text/html"
    data = Uri.parse("mailto:")
    putExtra(Intent.EXTRA_EMAIL, arrayOf(email))
    putExtra(Intent.EXTRA_SUBJECT, subject)
    putExtra(Intent.EXTRA_TITLE, subject)
}
if (packageManager != null && i.resolveActivity(packageManager) != null) {
    startActivity(i)
}

如果有人找到一个解决方案来显示消息…

这些解决方案对我都不起作用。这里有一个对棒棒糖有效的最小解决方案。在我的设备上，只有Gmail和本地电子邮件应用程序出现在最终的选择器列表中。

Intent emailIntent = new Intent(Intent.ACTION_SENDTO,
                                Uri.parse("mailto:" + Uri.encode(address)));

emailIntent.putExtra(Intent.EXTRA_SUBJECT, subject);
emailIntent.putExtra(Intent.EXTRA_TEXT, body);
startActivity(Intent.createChooser(emailIntent, "Send email via..."));

根据Android开发者官方文档，这是发送电子邮件意图的正确方式

添加以下代码行到你的应用程序:

Intent intent = new Intent(Intent.ACTION_SEND);//common intent 
intent.setData(Uri.parse("mailto:")); // only email apps should handle this

可选:添加主体和主题，就像这样

intent.putExtra(Intent.EXTRA_SUBJECT, "Your Subject Here");
intent.putExtra(Intent.EXTRA_TEXT, "E-mail body" );

你的问题里已经加了这句话

intent.putExtra(Intent.EXTRA_EMAIL, new String[]{"hello@example.com"});

这将是收件人的地址，这意味着用户将向您(开发人员)发送电子邮件。

这对我来说非常有效:

    Intent intent = new Intent(Intent.ACTION_VIEW);
    intent.setData(Uri.parse("mailto:" + address));
    startActivity(Intent.createChooser(intent, "E-mail"));