Emails not signed with DKIM?

Question

Domain Name System

Who faced DNS hosting from Yandex? How to set up sending emails from your hosting with a DKIM signature?
DNS records:
https://s.mail.ru/4izzV7bQKLMv/img-2016-03-17-07-5... Incoming mail
properties:
Received: from mxfront13h.mail.yandex.net ([127.0.0.1])
by mxfront13h.mail.yandex.net with LMTP id AP5L5o89
for <**@ya.ru>; Thu, 17 Mar 2016 07:36:28 +0300
Received: from sp2.siteko.net (sp2.siteko.net [95.213.161.147])
by mxfront13h.mail.yandex.net (nwsmtp/Yandex) with ESMTPS id asRTvxPjNS- aRNqNvP5;
Thu, 17 Mar 2016 07:36:27 +0300
(using TLSv1.2 with cipher DHE-RSA-AES256-SHA256 (256/256 bits))
(Client certificate not present)
Return-Path: [email protected]
X-Yandex-Front: mxfront13h.mail.yandex.net
X-Yandex-TimeMark: 1458189387
Authentication-Results: mxfront13h.mail.yandex.net; spf=pass (mxfront13h.mail.yandex.net: domain of con.network designates 95.213.161.147 as permitted sender) [email protected]; dkim=neutral [email protected]
X-Yandex-Spam: 1
DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=con.network; s=dkim;
h=Date:Message-Id:Content-Type:MIME-Version:Subject:From:Subject:To; bh=2dJvH7+3hPfSoAiQBH7iIC30Jovft0VqjiqlnvG72c8=;
b = xXuhbmkWf2NrwCuFyq3Qf0MJR3K3Jvsg / NbUynwz2bvssNzrm + 6hRf9JzV8H9UWNVKRfntQcGgRy6keB2MuiiCgSJ1fQuTvPXUe + esmHnyxM70nGo / oAKVN88Uk + LTh9xKHRAC4CZoSddMLGz61DUFBDAdhmLT2udRT29OFBYEc =;
Received: from manysour by sp2.siteko.net with local (Exim 4.80)
(envelope-from )
id 1agPff-0000VE-IE
for [email protected]; Thu, 17 Mar 2016 07:36:27 +0300

Answer 1

You have published a DKIM key for the mail selector (mail._domainkey) and the mail is signed with the dkim selector (s=dkim in DKIM-Signature). As far as I understand, the letter was formed by your server and it added the DKIM signature, not Yandex. Accordingly, either correct the selector in your mail server settings from dkim to mail (only suitable if you use the same key as Yandex) or publish the public key that it uses in the dkim._domainkey entry or use sending via SMTP Yandex with authorization, then he will sign the letters.