PHPMailer slow response time - php

Question

I'm using PHPMailer to send a forgot password email to users and when the user submits their email to the code below the page takes a few minutes to load!! Im not expecting the email to be send instantly but is there a way to make it so it will redirect the user while still sending the email?
I'm fairly new to php so there could be something simple I'm missing out.
Here is my code:
<?php
define('DB_NAME', '#######');
define('DB_USER', '#######');
define('DB_PASSWORD', '#######');
define('DB_HOST', 'localhost');
$conn = mysqli_connect(DB_HOST, DB_USER, DB_PASSWORD, DB_NAME);
if (!$conn) {
die('Could not connect: ' . mysqli_connect_error());
}
$recovery = $_POST['recovery'];
$sql = "SELECT forgotpass FROM members WHERE username = '$recovery'";
$result=mysqli_query($conn, $sql);
while($row = mysqli_fetch_array($result, MYSQLI_ASSOC))
{
echo "Please wait... ";
$mailto = $recovery;
$mailSub = "Here's your password!";
$mailMsg = $row['forgotpass'];
require 'PHPMailer-master/PHPMailerAutoload.php';
$mail = new PHPMailer();
$mail ->IsSmtp();
$mail ->SMTPDebug = 0;
$mail ->SMTPAuth = true;
$mail ->SMTPSecure = 'ssl';
$mail ->Host = "bemoresocial.co.uk";
$mail ->Port = 465; // or 587
$mail ->IsHTML(true);
$mail ->Username = "info#bemoresocial.co.uk";
$mail ->Password = "#########";
$mail ->SetFrom("info#bemoresocial.co.uk");
$mail ->Subject = $mailSub;
$mail ->Body = $mailMsg;
$mail ->AddAddress($mailto);
if(!$mail->Send())
{
echo "Something went wrong :(";
}
else
{
header('Location: ./success.php');
}
}
mysqli_close($conn);

Answer 1

SMTP can be slow, often deliberately so; it's really not well suited to sending email to remote servers during page submission processing, as PHP is typically used for.
The best way to fix this is to install a local mail server such as Postfix. Submitting messages to that (using SMTP to localhost) will be very fast, and then the mail server can deal with the slower onward delivery. This is effectively a queuing system, but is much easier than using something like beanstalkd, redis, or rabbitmq to build your own queue.
In your code, the require inside the while loop will cause a fatal error if it goes round more than once, because you will be requiring the same class file repeatedly. To send to multiple recipients efficiently, reuse the PHPMailer instance - you don't need to start from scratch every time around the loop - if you can use keepalive, this will also be much faster - see the mailing list example provided with PHPMailer for how to do that.
Though it's not part of the problem you're seeing, I can see you've based your code on an obsolete example, and you're using an old version of PHPMailer - upgrade to 6.0.

Answer 2

I ran into the same problem with VERY SLOW running PHP Mailer, like 3 minutes to send 15 emails using the Website Host SMTP server.
What I did to make it finish within seconds is to switch to gmail smtp. When you do this you'll need to go to Google and generate an app password Sign In Using App Password. So in your code use your normal email address with the generated password (note your normal password still works for your normal email access) and use tls security.
When I moved the program from testing to production the email failed. I found I had to go to google and just sign in and everything worked again.
Also note if you turn on SMTPDebug = 2; it will show you each step and the time it finished.
include ('class.PHPMailer.php');
$mail = new PHPMailer(true); // Passing `true` enables exceptions
try {
//Server settings
$mail->SMTPDebug = 0; // 0=no output, 1=Commands, 2=Data & Commands, 3=2+connection status 4=Low-Level data output
$mail->isSMTP(); // Set mailer to use SMTP
$mail->Host = 'smtp.gmail.com'; // Specify main and backup SMTP servers
$mail->SMTPAuth = true; // Enable SMTP authentication
$mail->Username = 'mickeymouse#gmail.com'; // SMTP username
$mail->Password = 'aaaabbbbccccdddd'; // SMTP password (used google Generated app password)
$mail->SMTPSecure = 'tls'; // Enable TLS encryption, `ssl` also accepted
$mail->Port = 587; // TCP port to connect to
// Recipients
$i = 0; $address="";
foreach($recipients as $i => $address)
{
$mail->addAddress($address);
}
$mail->addReplyTo('mickeymouse#gmail.com', 'Mickey');
$mail->isHTML(true);
$mail->setFrom('mickeymouse#gmail.com', 'Mickey');// Set email format to HTML
$mail->Subject = $subject;
$mail->Body = $body;
$mail->send();
$message = 'Message has been sent';
}
catch (Exception $e) {
$message = 'Message could not be sent.'."<br>".
'Mailer Error: ' . $mail->ErrorInfo;
}