在html和php中创建邮件表单

<form action="send_email.php" method="post">
  <label for="recipient">收件人邮箱地址：</label>
  <input type="email" id="recipient" name="recipient" required><br><br>
  
  <label for="subject">主题：</label>
  <input type="text" id="subject" name="subject" required><br><br>
  
  <label for="content">内容：</label><br>
  <textarea id="content" name="content" rows="5" cols="50" required></textarea><br><br>
  
  <input type="submit" value="发送邮件">
</form>

<?php
if ($_SERVER["REQUEST_METHOD"] == "POST") {
  $recipient = $_POST["recipient"];
  $subject = $_POST["subject"];
  $content = $_POST["content"];
  
  // 发送邮件
  $result = mail($recipient, $subject, $content);
  
  if ($result) {
    echo "邮件发送成功！";
  } else {
    echo "邮件发送失败！";
  }
}
?>