index.php

<?php
#Library for send messages for emails with files
namespace EmailSender;
require 'vendor/autoload.php';
use PHPMailer\PHPMailer\PHPMailer;

class EmailSender
{

    public function __construct(string $login, string $password, $name)
    {
        $this->login    = $login;
        $this->password = $password;
        $this->name     = $name;
        $this->mail     = new PHPMailer();
    }

    private function load()
    {
        $massiv = file('mail.txt');
        $string = implode(" ", $massiv);
        preg_match_all('/([a-z0-9_\.\-])+\@(([a-z0-9\-])+\.)+([a-zа-я0-9]{2,4})+/i', $string, $matches);
        return $matches;
    }

    public function send()
    {

        $matches = $this->load();
        foreach ($matches[0] as $match) {
            $this->mail->isSMTP(); // Set mailer to use SMTP
            $this->mail->Host       = 'smtp.mail.ru'; // Specify main and backup SMTP servers
            $this->mail->SMTPAuth   = true; // Enable SMTP authentication
            $this->mail->Username   = $this->login; // SMTP username
            $this->mail->CharSet    = "UTF-8";
            $this->mail->Password   = $this->password; // SMTP password
            $this->mail->SMTPSecure = 'tls'; // Enable TLS encryption, `ssl` also accepted
            $this->mail->Port       = 587; // TCP port to connect to

            //Recipients
            $this->mail->setFrom($this->login, $this->name);
            $this->mail->addAddress($match); // Add a recipient

            //Attachments
            $this->mail->addAttachment('2.jpg', 'new.jpg'); // Optional name

            //Content
            $this->mail->isHTML(true); // Set email format to HTML
            $this->mail->Subject = 'Предложение к сельхоз производителям';
            $this->mail->Body    = '123 321233213121';
            $this->mail->AltBody = 'This is the body in plain text for non-HTML mail clients';

            $this->mail->send();
            echo 'Message has been sent <br>';
            sleep(2);
        }

    }
}

$test = new EmailSender('[email protected]', 'secret', 'Stepan');

$test->send();