# SMTP Mail Setup and Troubleshooting Guide

https://fiberserver.net.tr/en/knowledgebase/article/smtp-mail-setup-troubleshooting

**In short:** like most hosting companies, Fiberserver keeps PHP's `mail()` function disabled, because it sends mail without any authentication and the messages end up in spam or get the server IP blacklisted. Send mail over authenticated SMTP instead: with the PHPMailer library in your own code, or through the SMTP settings of your application.

## Why mail() is disabled

The `mail()` function hands the message to the local mail system without a username, password or sender check. Receiving servers see a message that nobody has vouched for, mark it as spam, and when a script sends too many of them the server's IP address lands on blacklists that affect every customer on it. Authenticated SMTP sends through a real mailbox on your domain, so SPF and DKIM checks pass and the mail is trusted.

## Sending with PHPMailer

Download [PHPMailer](https://github.com/PHPMailer/PHPMailer) and include it in your project (with Composer: `composer require phpmailer/phpmailer`). A minimal sending script looks like this:

```
<?php
use PHPMailer\PHPMailer\PHPMailer;
require 'vendor/autoload.php';

$mail = new PHPMailer(true);
$mail->isSMTP();
$mail->Host       = 'mail.yourdomain.com';   // your mail server
$mail->SMTPAuth   = true;
$mail->Username   = 'name@yourdomain.com';   // a real mailbox
$mail->Password   = 'PASSWORD';
$mail->SMTPSecure = 'ssl';                   // 'ssl' for port 465, 'tls' for 587
$mail->Port       = 465;
$mail->CharSet    = 'utf-8';
$mail->setFrom('name@yourdomain.com', 'Your Name');
$mail->addAddress('recipient@example.com');
$mail->isHTML(true);
$mail->Subject = 'Subject line';
$mail->Body    = 'Message body';

if (!$mail->send()) {
    echo 'Mailer error: ' . $mail->ErrorInfo;
} else {
    echo 'Message sent';
}
```

Set `$mail->SMTPDebug = 2;` while testing to see the full conversation with the server. The sender address must be a mailbox that exists on the domain you send from; sending as a Gmail address through your own server will fail SPF.

## Gmail and Yandex settings

- **Gmail:** host `smtp.gmail.com`, port 465 with SSL (or 587 with TLS); use an app password, not your account password.
- **Yandex:** host `smtp.yandex.com`, port 587 with TLS.

## SMTP settings in popular applications

Most applications ship with PHPMailer or a similar library and only need the SMTP details in their admin panel. On a Fiberserver hosting account the host is `localhost` or `mail.yourdomain.com`, the port is 465 (SSL) and the login is the mailbox and its password.

- **WordPress:** install the WP Mail SMTP plugin. Mailer: SMTP, host `localhost`, port 465, encryption SSL, authentication on, username and password of the mailbox.
- **vBulletin:** Options → Email Options → "Send emails via SMTP server": server `mail.yourdomain.com`, port 465, SSL, mailbox and password.
- **SMF:** Admin → Maintenance → Mail: type SMTP, server `ssl://localhost`, port 465, mailbox and password.
- **OpenCart:** System → Settings → Mail: protocol SMTP, host `ssl://localhost`, port 465, mailbox and password.

Other applications use the same four values: host, port, mailbox, password.

## If mail still goes to spam

Check that your domain has SPF, DKIM and DMARC records; our [SPF, DKIM and DMARC guide](https://fiberserver.net.tr/en/knowledgebase/article/how-spf-dkim-dmarc-work) explains them. For newsletters and bulk sending use a dedicated service such as our [SMTP sending plans](https://fiberserver.net.tr/en/email-sending-plans) rather than the hosting mailbox.