How to parse email to application inbox?

I dont quite understand the question ... why you could not just render it with liek a regular view ? maybe I am not getting the architecture right

Sorry, probably my language limitations make difficult to explain the idea.

1. User A sends a message from the portal, which is saved to the database, but at the same time it is sent to the private email address of the recipient-user B.
2. User B receives a message and responds from his e-mail program to this message, but not to the recipient's private e-mail, but only to the e-mail address of the service.
3. The site downloads all messages from its mailbox and parses them to save to the database and assign it as a reply to a specific thread and user.

My question is how to achieve this functionality?

I think that:

1. In step 1 I should send message with reply address with hash, so I can later by that hash assign it to thread and user, for example: [email protected]
2. Server should be configured to catch that email even if mailbox [email protected] doesnt exist. That could be the problem for me. I don`t know how to achieve that. Maybe all incoming emails should be redirected to one common portal email address?
3. I can download message by IMAP and using hash in email address assign it to thread and user.

Is it a good solution or maybe it is better way to do that? If it is good I need a prompt in second step- how to configure it like that.

You need to have the mail arrive in a regular email account and then build pop or imap functionality into your application.

In the past I have reliably used the library php-imap/php-imap

https://packagist.org/packages/php-imap/php-imap

You can open a mailbox, grab the messages and delete them from the mailbox in about 10 lines of code.

Regarding the missing mailboxes, most hosts will allow you to setup a catch-all mailbox that all unknown recipients goes into. You will though expect to get a lot of spam in there so you will probably need something in the body of the email to tell you it is definitely one of yours.

I want to do it like that, but how to assign message to specific thread/user?

You can check the headers for who it was to. The Library will do that.

You see helpdesk tickets say "don't change the subject" or a line in the body like

======== Do not remove this @hsys72300dhdjasj ========

which you can easily find with a regex

Ok, this is a solution, but it depends on whether the user actually does not remove something (even accidentally) from the content of the message. Would not such a virtual reply address with hash be a better (more fool-proof) solution? The problem is how to set it?

I've said.

Regarding the missing mailboxes, most hosts will allow you to setup a catch-all mailbox that all unknown recipients goes into.

Ok, sorry I missed it somehow. Thank you- that solves my question entirely.