Yandex cuts headers, how to find out who the letter was originally sent to?

Question

Yandex.Mail for domain

We work in Yandex.Connect. We started the info team, respectively, everything that comes to info is scattered throughout the team in personal mail. But here's the problem - there is not a single mention of info in the mail headers (not only the To header is empty, but in all recieved ones). How in this case to determine whether only the letter came to the current mailbox (from which it was taken), or whether it was forwarded with info ?? Is it really just a reconciliation with the next box: "is there such a letter there too?"
Headers ([email protected] - this is not our mailbox, just sent to them and us, but only they are indicated in to):

'texthtml' => string 'Received: from mxback1g.mail.yandex.net (localhost [127.0.0.1])
  by mxback1g.mail.yandex.net with LMTP id H3xCq7FU6F-NpRFwlU3;
  Wed, 10 Jul 2019 11:54:02 +0300
Received: from mxback1g.mail.yandex.net (localhost.localdomain [127.0.0.1])
  by mxback1g.mail.yandex.net (Yandex) with ESMTP id 0CBD71481239;
  Wed, 10 Jul 2019 11:54:02 +0300 (MSK)
X-Yandex-Internal: 1
Received: from localhost (localhost [::1])
  by mxback1g.mail.yandex.net (nwsmtp/Yandex) with ESMTP id dE2gcwqwHK-q1V7C3dN;
  Wed, 10 Jul 2019 11:54:01 +0300
X-Yandex-Front: mxback1g.mail.yandex.net
X-Yandex-TimeMark: 1162548721.497
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex.ru; s=mail; t=1572748121;
Authentication-Results: mxback1g.mail.yandex.net; dkim=pass [email protected]
X-Yandex-MXCode: RU MOW
X-Yandex-Suid-Status: 1 1110000051946207,1 
X-Yandex-Spam: 1
X-Yandex-Envelope: aGVsbz1teGJhY2sxZQo=
X-Yandex-Sender-Uid: 121787844
Received: by myt6-5dca55ddb3f8.qloud-c.yandex.net with HTTP;
  Wed, 10 Jul 2019 11:53:01 +0300
From: =?utf-8?---=?= <[email protected]>
To: [email protected]
In-Reply-To: <[email protected]>
Subject: 
MIME-Version: 1.0
X-Mailer: Yamail [ http://yandex.ru ] 5.0
Date: Wed, 10 Jul 2019 11:52:01 +0300
Message-Id: <[email protected]>
Content-Transfer-Encoding: 8bit
Content-Type: text/html; charset=utf-8
Return-Path: [email protected]
X-Yandex-Forward: 9e12fg06a3f2a45bdd7efaa01560daf7
X-Yandex-Forward: b50714099c5b9984335dae755ad41331
X-Yandex-Forward: 845b0a1185230db556e1ce27dff36f3c

Answer 1

In general, unfortunately not.
Usually, when delivering to the box, the Delivered-To header is affixed, but there is no standard regulating the affixing of this header, and Yandex does not affix it.
In the case when the letter has only one recipient, it will appear in the Received header.
Alternatively, you can try forwarding letters from the [email protected] mailbox to another mailbox, so that the forward has a single recipient and it is lit in Received, and forward from this mailbox further. Not sure if this will work in all cases (eg for local/non-local emails).

Answer 2

Why analyze it?
You work in the connection according to the conditions that they provide, you stumble on the settings - you get the result and the expected behavior in practice. What for to you to climb and analyze headings of the message. If you somehow want to get involved with her, then this is a very dubious idea. The mailer works according to its internal rules, sends messages between its cluster members. These rules are subject to change. Moreover, the mailer can at the exit, before putting the letter in your mailbox, cut all the headers, make a kind of masquerade. You don't control it in any way. If you want more advanced work with mail, manage it, then you need to look for another service, or raise your own mail servers. Either a person or organization has been hired to send and process mail to you for money, as you wish, if you need details,
By the way. You remember that you are just a guinea pig teaching the big Yandex mail machine with your behavior, clicking on the spam button and other actions.
So, for example, the owner of another mail for the domain, who delegated it to Yandex in a simple way, can generally send you letters on behalf of other organizations, domains. Let's say I can send you letters on behalf of your supplier, and you will see them as letters from your supplier in the mail, until you start wooling the letter headers, you won't understand. But who in the modern age of technology looks at the headers of emails?..
You run from Yandex if mail is a significant tool in your work.
Mail, like cheese, is never free. And if it's free, then look for how you indirectly pay for it. In Yandex, you have a very unreliable tool, which, moreover, is not controlled by you in any way more than the methods that Yandex has provided you. This means that you will click the spam button on every spam letter until you lose your pulse, and spam will not decrease. They do not provide harsh filters for masks, ip and other joys. You can bombard mail with php and python scripts and you can't do anything about it.
But, on the other hand, you will work for free for the great Yandex spam machine.