php判断邮箱地址是否存在的方法_PHP
PHP校验邮箱地址的方法很多， 比较常用的就是自己写正则了， 不过正则多麻烦， 我PHP自带了方法做校验。
filter_var
filter_var是PHP内置的一个变量过滤的方法， 提供了很多实用的过滤器， 可以用来校验整数、浮点数、邮箱、URL、MAC地址等。
具体的过滤器参考: filters.validate
filter_var如果返回false, 说明变量无法通过过滤器， 也就是不合法了。
$email = "lastchiliarch@163.com"; var_dump(filter_var($email, FILTER_VALIDATE_EMAIL)); $email = "asb"; var_dump(filter_var($email, FILTER_VALIDATE_EMAIL)); $email = "1@a.com"; var_dump(filter_var($email, FILTER_VALIDATE_EMAIL)); 输出： string(21) "lastchiliarch@163.com" bool(false) string(7) "1@a.com"
对于asb这种非法邮箱格式返回了false, 但对于1@a.com则通过了，还是略有瑕疵啊。
不过一般的正则也通过会认为1@a.com是一个合法的邮箱， 那有啥办法可以更精准的验证呢？
checkdnsrr
checkdnsrr其实是用来查询指定的主机的DNS记录的，我们可以借用它来验证邮箱是否存在。
对于1@a.com肯定是MX记录不存在的。
$email = "lastchiliarch@163.com";
var_dump(checkdnsrr(array_pop(explode("@",$email)),"MX"));
$email = "1@a.com";
var_dump(checkdnsrr(array_pop(explode("@",$email)),"MX"));
输出:
bool(true)
bool(false)
可以看到， 很完美， 唯一的缺点就是太慢了， 毕竟是要做一次网络请求。 所以不适合同步对大量的邮箱采用这种做法去校验。
filter_var+checkdnsrr
我们可以接合filter_var 和checkdnsrr做校验， 对于绝大多数的非法邮箱肯定会在filter_var的时候就挂掉了， 剩下的再用
checkdnsrr进一步判断。
$email_arr = array("lastchiliarch@163.com", "1@a.com");
foreach($email_arr as $email) {
if (filter_var($email) === false) {
echo "invalid email: $email \n";
continue;
}
if(checkdnsrr(array_pop(explode("@",$email)),"MX") === false) {
echo "invalid email: $email \n";
continue;
}
}
输出: invalid email: 1@a.com
但要注意的是， 由于只是检查MX记录， 所以只能判断163.com是存在的， 但不能说明lastchiliarch这个用户是存在的。
想要更精确的判断邮箱存在， 那只能连接到smtp服务器去验证了。
下面为大家分享的php邮箱地址正则表达式验证，具体内容如下
<?php
header ( "Content-Type: text/html; charset=UTF-8" );
$reply = "";
if ( isset($_POST["email_address"]) )
{
$email_address = $_POST["email_address"];
$pattern = "/^([0-9A-Za-z\\-_\\.]+)@([0-9a-z]+\\.[a-z]{2,3}(\\.[a-z]{2})?)$/i";
if ( preg_match( $pattern, $email_address ) )
{
$reply = "您输入的电子邮件地址合法<br /><br />\n";
$user_name = preg_replace( $pattern ,"$1", $email_address );
$domain_name = preg_replace( $pattern ,"$2", $email_address );
$reply .= "用户名：".$user_name."<br />\n";
$reply .= "域名：".$domain_name."<br />\n\n";
}
else
{
$reply = "您输入的电子邮件地址不合法";
}
}
?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="zh" xml:lang="zh">
<head>
<title>电子邮件地址验证程序</title>
</head>
<body style="text-align: center;">
<h1 id="电子邮件地址验证程序">电子邮件地址验证程序</h1>
<form action="#" method="post">
请输入电子邮件地址：<input name="email_address" type="text" style="width: 300px;" /><br />
<input type="submit" value="验证电子邮件地址" />
</form>
<?php
echo $reply;
?>
</body>
</html>希望大家喜欢这篇文章，对大家有所帮助。
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
1664
14
1423
52
1317
25
1268
29
1246
24
PHP and Python: Comparing Two Popular Programming Languages
Apr 14, 2025 am 12:13 AM
PHP and Python each have their own advantages, and choose according to project requirements. 1.PHP is suitable for web development, especially for rapid development and maintenance of websites. 2. Python is suitable for data science, machine learning and artificial intelligence, with concise syntax and suitable for beginners.
Explain secure password hashing in PHP (e.g., password_hash, password_verify). Why not use MD5 or SHA1?
Apr 17, 2025 am 12:06 AM
In PHP, password_hash and password_verify functions should be used to implement secure password hashing, and MD5 or SHA1 should not be used. 1) password_hash generates a hash containing salt values to enhance security. 2) Password_verify verify password and ensure security by comparing hash values. 3) MD5 and SHA1 are vulnerable and lack salt values, and are not suitable for modern password security.
PHP in Action: Real-World Examples and Applications
Apr 14, 2025 am 12:19 AM
PHP is widely used in e-commerce, content management systems and API development. 1) E-commerce: used for shopping cart function and payment processing. 2) Content management system: used for dynamic content generation and user management. 3) API development: used for RESTful API development and API security. Through performance optimization and best practices, the efficiency and maintainability of PHP applications are improved.
PHP: A Key Language for Web Development
Apr 13, 2025 am 12:08 AM
PHP is a scripting language widely used on the server side, especially suitable for web development. 1.PHP can embed HTML, process HTTP requests and responses, and supports a variety of databases. 2.PHP is used to generate dynamic web content, process form data, access databases, etc., with strong community support and open source resources. 3. PHP is an interpreted language, and the execution process includes lexical analysis, grammatical analysis, compilation and execution. 4.PHP can be combined with MySQL for advanced applications such as user registration systems. 5. When debugging PHP, you can use functions such as error_reporting() and var_dump(). 6. Optimize PHP code to use caching mechanisms, optimize database queries and use built-in functions. 7
How does PHP handle file uploads securely?
Apr 10, 2025 am 09:37 AM
PHP handles file uploads through the $\_FILES variable. The methods to ensure security include: 1. Check upload errors, 2. Verify file type and size, 3. Prevent file overwriting, 4. Move files to a permanent storage location.
The Enduring Relevance of PHP: Is It Still Alive?
Apr 14, 2025 am 12:12 AM
PHP is still dynamic and still occupies an important position in the field of modern programming. 1) PHP's simplicity and powerful community support make it widely used in web development; 2) Its flexibility and stability make it outstanding in handling web forms, database operations and file processing; 3) PHP is constantly evolving and optimizing, suitable for beginners and experienced developers.
How does PHP type hinting work, including scalar types, return types, union types, and nullable types?
Apr 17, 2025 am 12:25 AM
PHP type prompts to improve code quality and readability. 1) Scalar type tips: Since PHP7.0, basic data types are allowed to be specified in function parameters, such as int, float, etc. 2) Return type prompt: Ensure the consistency of the function return value type. 3) Union type prompt: Since PHP8.0, multiple types are allowed to be specified in function parameters or return values. 4) Nullable type prompt: Allows to include null values and handle functions that may return null values.
PHP vs. Python: Understanding the Differences
Apr 11, 2025 am 12:15 AM
PHP and Python each have their own advantages, and the choice should be based on project requirements. 1.PHP is suitable for web development, with simple syntax and high execution efficiency. 2. Python is suitable for data science and machine learning, with concise syntax and rich libraries.
