PHPMailer not sending emails to Gmail addresses

Other Questions Gmail
1

I’m having trouble with my email sending script. It works fine when I test it on my local server, but when I try to send emails to Gmail accounts, nothing happens. I’ve also tested it on a live server and Gmail still doesn’t receive the messages.

if($query_result) {
    include("includes/PHPMailerAutoload.php");
    $mailer = new PHPMailer();
    $mailer->isSMTP();
    $mailer->SMTPDebug = 1;
    $mailer->SMTPAuth = true;
    $mailer->SMTPSecure = 'ssl';
    $mailer->Host = "smtp.example.com";
    $mailer->Port = 465;
    $mailer->isHTML(true);
    $mailer->Username = "[email protected]";
    $mailer->Password = "mypassword";
    $mailer->setFrom("[email protected]");
    $mailer->Subject = "Account Registration";
    $mailer->Body = "<div style='background:#0066cc; padding:15px; width:600px;'>
        <div style='background:white; padding:20px;'>
            <h2>Welcome to $site_name</h2>
            <p>Your account details:</p>
            <p>Email: $user_email</p>
            <p>Password: $user_password</p>
            <p><a href='$site_url/verify.php?token=".$verification_token."'>Activate Account</a></p>
        </div>
    </div>";
    $mailer->addAddress($user_email);
    
    if(!$mailer->send()) {
        echo "Error: " . $mailer->ErrorInfo;
    } else {
        echo "<script>location.href='success.php';</script>";
    }
}

Is there something wrong with my configuration? Do I need to modify the mailer settings for Gmail specifically?

2

gmail’s notorious for slow delivery or silently dumping emails in spam. check your spam/junk folder first - i’ve had emails show up there hours late. also, crank your smtp debug from 1 to 2 or 3. you’ll get way more detailed error messages that’ll show what’s actually breaking during send.

3

Check your mail server’s reputation and authentication settings. Gmail’s filtering is brutal - they’ll block servers without proper TLS or anything that looks suspicious. Your SMTP config looks fine, but try port 587 with STARTTLS instead of SSL on 465. Most hosting providers have better luck with that setup. Also make sure your host actually allows outbound SMTP - some shared hosts just block port 465 completely. I’ve hit this exact issue where emails worked locally but died on production because of firewall restrictions. Honestly, you might want to just use SendGrid or Mailgun instead - they’ve got way better deliverability with Gmail.

4

Gmail’s gotten super picky about email filtering lately - they’ll block messages from servers that don’t have proper authentication set up. I’ve dealt with this before and it’s usually an SPF, DKIM, or DMARC issue with your domain setup. Gmail’s spam filters are brutal - they’ll just silently drop emails that fail these checks instead of even putting them in spam. Check if your server’s IP is blacklisted and make sure you’ve got reverse DNS configured properly. I’d test with a different email provider first to confirm your code works, then tackle the domain authentication stuff. Getting those DNS records set up right takes time to propagate, but it almost always fixes Gmail delivery problems.