我现在更喜欢使用 SMTP 发送批量电子邮件。在发送邮件之前,我需要检查这些邮件 ID 是否有效。我有一个代码来检查它,我在下面添加了它。它来自 Github。我只需要通过使用此 DNS 端口检查与您确认所有这些,当检查大量无效邮件时,它是否会使我们的服务器陷入黑名单等问题?
<?php
function verifyEmail($toemail, $fromemail, $getdetails = false){
$email_arr = explode("@", $toemail);
$domain = array_slice($email_arr, -1);
$domain = $domain[0];
// Trim [ and ] from beginning and end of domain string, respectively
$domain = ltrim($domain, "[");
$domain = rtrim($domain, "]");
if( "IPv6:" == substr($domain, 0, strlen("IPv6:")) ) {
$domain = substr($domain, strlen("IPv6") + 1);
}
$mxhosts = array();
if( filter_var($domain, FILTER_VALIDATE_IP) )
$mx_ip = $domain;
else
getmxrr($domain, $mxhosts, $mxweight);
if(!empty($mxhosts) )
$mx_ip = $mxhosts[array_search(min($mxweight), $mxhosts)];
else {
if( filter_var($domain, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4) ) {
$record_a = dns_get_record($domain, DNS_A);
}
elseif( filter_var($domain, FILTER_VALIDATE_IP, FILTER_FLAG_IPV6) ) {
$record_a = dns_get_record($domain, DNS_AAAA);
}
if( !empty($record_a) )
$mx_ip = $record_a[0]['ip'];
else {
$result = "invalid";
$details .= "No suitable MX records found.";
return ( (true == $getdetails) ? array($result, $details) : $result );
}
}
$connect = @fsockopen($mx_ip, 25);
if($connect){
if(preg_match("/^220/i", $out = fgets($connect, 1024))){
fputs ($connect , "HELO $mx_ip\r\n");
$out = fgets ($connect, 1024);
$details .= $out."\n";
fputs ($connect , "MAIL FROM: <$fromemail>\r\n");
$from = fgets ($connect, 1024);
$details .= $from."\n";
fputs ($connect , "RCPT TO: <$toemail>\r\n");
$to = fgets ($connect, 1024);
$details .= $to."\n";
fputs ($connect , "QUIT");
fclose($connect);
if(!preg_match("/^250/i", $from) || !preg_match("/^250/i", $to)){
$result = "invalid";
}
else{
$result = "valid";
}
}
}
else{
$result = "invalid";
$details .= "Could not connect to server";
}
if($getdetails){
return array($result, $details);
}
else{
return $result;
}
}
?>
如果您有更好的想法,请帮助我。