php正则表达式验证E-mail地址

[php]代码库

$email = "test@ansoncheung.tk";  
if (preg_match('/^[^0-9][a-zA-Z0-9_]+([.][a-zA-Z0-9_]+)*[@][a-zA-Z0-9_]+([.][a-zA-Z0-9_]+)*[.][a-zA-Z]{2,4}$/',$email)) {  
    echo "Your email is ok.";  
} else {  
    echo "Wrong email address format";  
}