Fetch is a library for reading email and attachments, primarily using the POP and IMAP protocols.
Fetch was part of a large project, Mortar, which is hosted on Google Code. It is currently being migrated over to Github, as well as being updated to support modern php features. While the project is in flux I encourage you to try it out, but be careful about using it in a production environment without proper testing.
This is just a simple code to show how to access messages by using Fetch. It uses Fetch own autoload, but it can (and should be, if applicable) replaced with the one generated by composer.
require 'autoload.php';
$server = new \Fetch\Server('imap.example.com', 993);
$server->setAuthentication('dummy', 'dummy');
$messages = $server->getMessages();
/** @var $message \Fetch\Message */
foreach ($messages as $message) {
echo "Subject: {$message->getSubject()}\nBody: {$message->getMessageBody()}\n";
}