SMTP configuration on Plesk Server (Centos) - smtp

Question

I'm trying to make code to send a simple mail via SMTP, I read that I must use the class phpmailer and also install pear engine on the server root, I downloaded some different files to authenticate the SMTP but always requires more files that I don't have or cant be charged. Actually, the PHP errors display this:
Warning: require_once(): open_basedir restriction in effect. File(/opt/plesk/php/7.1/share/pear/PEAR.php) is not within the allowed path(s): (/var/www/vhosts/necotec.es/:/tmp/) in /var/www/vhosts/necotec.es/httpdocs/prueba_smtp/Mail.php on line 48
Warning: require_once(/opt/plesk/php/7.1/share/pear/PEAR.php): failed to open stream: Operation not permitted in /var/www/vhosts/necotec.es/httpdocs/prueba_smtp/Mail.php on line 48
Fatal error: require_once(): Failed opening required 'PEAR.php' (include_path='.:/opt/plesk/php/7.1/share/pear') in /var/www/vhosts/necotec.es/httpdocs/prueba_smtp/Mail.php on line 48
I dont know if cant be found or is a permision problem the files by default takes 644 permisions in this server. Any clue would be helpfull thanks.

Answer 1

open_basedir restriction in effect
error means that some files or scripts are located out of allowed directory.
In your case this file is /opt/plesk/php/7.1/share/pear/PEAR.php.
In Plesk you can disable open_basedir(not secure): Domains > example.com > PHP Settings and set open_basedir to none.
Another way(more secure) is to set open_basedir as {WEBSPACEROOT}{/}{:}{TMP}{/}:/opt/plesk/php/7.1
I was able to configure PHPMailer on my test server(Plesk 17.5-17.8) using steps:
Logged in to the server using SSH
Went to domain Document root directory: # cd /var/www/vhosts/example.com/httpdocs/
Run the command taken from github: # composer require phpmailer/phpmailer
As a result "vendor" folder appeared in "httpdocs" folder.
Created a testmail.php file based on 0-send-email-plesk.php:
<?php
use PHPMailer\PHPMailer\PHPMailer;
use PHPMailer\PHPMailer\Exception;
//Load Composer's autoloader
require 'vendor/autoload.php';
$mail = new PHPMailer;
$mail->isSMTP();
$mail->SMTPDebug = 2; # 0 off, 1 client, 2 client y server
$mail->CharSet = 'UTF-8';
$mail->Host = 'localhost';
$mail->Port = 25;
$mail->SMTPSecure = 'tls'; # SSL is deprecated
$mail->SMTPOptions = array (
'ssl' => array(
'verify_peer' => true,
'verify_depth' => 3,
'allow_self_signed' => true,
'peer_name' => 'Plesk',
)
);
$mail->SMTPAuth = true;
$mail->Username = 'sender#example.com';
$mail->Password = 'password';
$mail->setFrom('sender#example.com', 'Name Surname');
$mail->addAddress('recipient#domain.tld', 'Name Surname');
$mail->Subject = 'Email subject';
$mail->msgHTML('Email content with <strong>html</strong>');
if (!$mail->send()) {
echo "Mailer Error: " . $mail->ErrorInfo;
} else {
echo "Message sent!";
}
?>
It assumes that local mail server is used and Default Plesk self signed certificate is used by mail server: Plesk > Tools & Settings > SSL/TLS Certificates > Certificate for securing mail