composer require php-mime-mail-parser/php-mime-mail-parser

<?php
//We need to add the library first !
require_once __DIR__.'/vendor/autoload.php';

$path = 'path/to/mail.txt';
$Parser = new PhpMimeMailParser\Parser();

//There are three input methods of the mime mail to be parsed
//specify a file path to the mime mail :
$Parser->setPath($path); 

// Or specify a php file resource (stream) to the mime mail :
$Parser->setStream(fopen($path, "r"));

// Or specify the raw mime mail text :
$Parser->setText(file_get_contents($path));

// We can get all the necessary data
$to = $Parser->getHeader('to');
$from = $Parser->getHeader('from');
$subject = $Parser->getHeader('subject');

$text = $Parser->getMessageBody('text');
$html = $Parser->getMessageBody('html');
$htmlEmbedded = $Parser->getMessageBody('htmlEmbedded'); //HTML Body included data

// and the attachments also
$attach_dir = '/path/to/save/attachments/';
$Parser->saveAttachments($attach_dir);

// loop the attachments
$attachments = $Parser->getAttachments();
if (count($attachments) > 0) {
	foreach ($attachments as $attachment) {
		echo 'Filename : '.$attachment->getFilename().'<br />'; // logo.jpg
		echo 'Filesize : '.filesize($attach_dir.$attachment->getFilename()).'<br />'; // 1000
		echo 'Filetype : '.$attachment->getContentType().'<br />'; // image/jpeg
	}
}

?>