I want to setup a similar message structure as in github, where a user can either respond by email or logging into his account.
Github appears to have a unique-id in the reply-to field:
reply+i-39945717-887b26ec5b3de79d00dec7ef29ad308795b85685-6876349@reply.github.com Is it possible to add a unique ID to the "Reply-to"-header with swift-mailer?
How would the mail server be able to work with this?
For responding to using email, you can use In-Reply-To alongside Reply-To.
For this purpose you can use this StackOverFlow answer: Correct headers for replying and forwarding emails
In summary you need to track your message using its ID and its id is stored in In-Reply-To and this is the way you can set it:
$headers = $message->getHeaders(); $headers->addTextHeader('In-Reply-To', $previousEmail->getHeaders()->getMessageId()); Well, why not? Setting Reply-to with SwiftMailer is quite easy:
<?php $message = new \Swift_Message(); $message->setReplyTo(sprintf( 'reply+%[email protected]', uniqid() )); The uniquid() call is just for example. In real-life code you'd persist the entity ID beforehand (e.g. when you save it), and retrieve it from your model object later.
However, you'll need to set up a mail checker that would receive your incoming mail, parse it and transform into CRUD operations on your database.
+ sign is allowed there, and the mail should be received by the alias without the + sign and the suffix.