Why does corporate mail end up in "Junk" on outlook.com?

Question

Mail server

Good day, colleagues.
For more than one month I have been struggling with the problem that mail sent from my corporate server ALWAYS ends up in the Junk folder in outlook.com.
What we have:
Own corporate mail server, hosted by DigitalOcean based on mail in a box software.
Correctly configured SPF, DKIM, DMARK.
Test mailing to the same mail-tester.com knocks out 10 out of 10 points.
Problem:
When sending mail to an addressee at ***@outlook.com, in 100% of cases I find a letter in the Junk folder
. it is necessary to communicate with clients at whom boxes on Outlook.
Communication with outlook support comes down to the fact that they shrug, they say, we are not in business, this is our dofiga smart spam filter to blame. For their part, of course, they do not intend to do anything.
I am attaching the source of the message.

spoiler

Received: from CO1NAM04HT070.eop-NAM04.prod.protection.outlook.com
(2603:10a6:7:3d::18) by HE1PR0201MB2315.eurprd02.prod.outlook.com with HTTPS
via HE1PR09CA0074.EURPRD09.PROD.OUTLOOK.COM; Mon, 17 Sep 2018 06:21:44 +0000
Received: from CO1NAM04FT060.eop-NAM04.prod.protection.outlook.com
(10.152.90.53) by CO1NAM04HT070.eop-NAM04.prod.protection.outlook.com
(10.152.91.137) with Microsoft SMTP Server (version=TLS1_2,
cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384_P256) id 15.20.1164.13; Mon, 17
Sep 2018 06:21:43 +0000
Authentication-Results: spf=pass (sender IP is ___)
smtp.mailfrom=___; outlook.com; dkim=pass (signature was verified)
header.d=___;outlook.com; dmarc=pass action=none header.from=___;
Received-SPF: Pass (protection.outlook.com: domain of ___ designates
___ as permitted sender) receiver=protection.outlook.com;
client-ip=___; helo=box2.___;
Received: from box2.___ (___) by
CO1NAM04FT060.mail.protection.outlook.com (10.152.91.116) with Microsoft SMTP
Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384_P384) id
15.20.1164.13 via Frontend Transport; Mon, 17 Sep 2018 06:21:42 +0000
X-IncomingTopHeaderMarker: OriginalChecksum:()
(using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits))
(No client certificate requested)
by box2.___ (Postfix) with ESMTPSA id 409E8E12B3;
Mon, 17 Sep 2018 13:21:40 +0700 (+07)
DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=___; s=mail1;
t=1537165300; bh=rrJTpOAzob0lueug5EpulwvHWzmunzcNXBBjYqe0JDA=;
h=Date:From:To:Subject:From;
b=____
Content-Type: text/plain; charset="UTF-8"; format=flowed
Content-Transfer-Encoding: 8bit
Date: Mon, 17 Sep 2018 13:21:39 +0700
From: [email protected]___
To: [email protected], [email protected]
Subject: =
Message-ID: <@___>
X-Sender: [email protected]___
X-IncomingHeaderCount: 11
Return-Path: [email protected]___
X-MS-Exchange-Organization-ExpirationStartTime: 17 Sep 2018 06:21:43.2561
(UTC)
X-MS-Exchange-Organization-ExpirationStartTimeReason: Original Submit
X-MS-Exchange-Organization-ExpirationInterval: 2:00:00:00.0000000
X-MS-Exchange-Organization-ExpirationIntervalReason: Original Submit
X-MS-Exchange-Organization-Network-Message-Id: __
X-EOPAttributedMessage: 0
X-EOPTenantAttributedMessage: 84df9e7f-e9f6-40af-b435-aaaaaaaaaaaa:0
X-MS-Exchange-Organization-MessageDirectionality: Incoming
X-Microsoft-Exchange-Diagnostics: 1;CO1NAM04FT060;1:++/
X-Forefront-Antispam-Report: EFV:NLI;
X-MS-Exchange-Organization-AuthSource:
CO1NAM04FT060.eop-NAM04.prod.protection.outlook.com
X-MS-Exchange-Organization-AuthAs: Anonymous
X-MS-PublicTrafficType: Email
X-MS-Office365-Filtering-Correlation-Id: ___
X-Microsoft-Antispam:
BCL:0;PCL:0;RULEID:(5000110)(711020)(4605076)(610169)(650170)(651021)(8291501071);SRVR:CO1NAM04HT070;
X-Microsoft-Exchange-Diagnostics:
1;CO1NAM04HT070;3:+_
X-MS-TrafficTypeDiagnostic: CO1NAM04HT070:
X-MS-Exchange-EOPDirect: true
X-Sender-IP: ___
X-SID-PRA: [email protected]___
X-SID-Result: PASS
X-MS-Exchange-Organization-PCL: 2
X-Exchange-Antispam-Report-Test: UriScan:;
X-Exchange-Antispam-Report-CFA-Test:
BCL:0;PCL:0;RULEID:(444111676)(52401380)(52601095)(52505095)(52406095)(88860193)(82015058);SRVR:CO1NAM04HT070;BCL:0;PCL:0;RULEID:;SRVR:CO1NAM04HT070;
X-Microsoft-Exchange-Diagnostics:__
X-Microsoft-Antispam-Message-Info:__
X-Microsoft-Exchange-Diagnostics:__
X-OriginatorOrg: outlook.com
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 17 Sep 2018 06:21:42.9436
(UTC)
X-MS-Exchange-CrossTenant-Network-Message-Id: 
X-MS-Exchange-CrossTenant-Id: 
X-MS-Exchange-CrossTenant-FromEntityHeader: Internet
X-MS-Exchange-CrossTenant-RMS-PersistedConsumerOrg:
d4d70346-2c10-4f39-8c00-e767963926d9
X-MS-Exchange-Transport-CrossTenantHeadersStamped: CO1NAM04HT070
X-MS-Exchange-Transport-EndToEndLatency: 00:00:01.6963961
X-MS-Exchange-Processed-By-BccFoldering: 15.20.1143.017
X-Microsoft-Exchange-Diagnostics:
X-Microsoft-Antispam-Mailbox-Delivery:
abwl:0;wl:0;pcwl:0;kl:0;iwl:0;dwl:0;dkl:0;rwl:0;ucf:0;jmr:0;ex:0;auth:1;dest:J;OFR:SpamFilterAuthJ;ENG:(5062000261)(5061607266)(5061608174)(4900095)(4920089)(6375004)(4950130)(4990090)(9140004);RF:JunkEmail;
X-Message-Info:
X-Microsoft-Antispam-Message-Info:
MIME-Version: 1.0

Answer 1

Is there an MX record for your domain?
Is there an A-record for the domain name specified in the MX-record?
Is there a PTR record for the IP address from the A-record of the domain name specified in the MX-record?

Answer 2

Because Microsoft and Yahoo love to downplay incoming mail.
The way out is to ask each time the recipients to mark the mail as not spam. Should help over time.
If you have everything else, of course, in perfect order.