php正则表达式检查邮件地址是否正确
function checkEmail($email) { // Create the syntactical validation regular expression $regexp = "^([_a-z0-9-]+)(\.[_a-z0-9-]+)*@([a-z0-9-]+)(\.[a-z0-9-]+)*(\.[a-z]{2,4})$"; // Presume that the email is invalid $valid = 0; // Validate the syntax if (eregi($regexp, $email)) { list($username,$domaintld) = split("@",$email); // Validate the domain if (getmxrr($domaintld,$mxrecords)) $valid = 1; } else { $valid = 0; } return $valid; }