Why can mail.ru swear at DKIM?

Question

Mail server

Exchange Online is available, until recently everything went to the mailbox without problems, but you receive a rebuff that the letter was not sent.



Error Details
Reported error: 550 5.7.23 The message was rejected because of Sender Policy Framework violation -> 550 5.7.1 This message was not accepted due to domain (******.com) owner DMARC policy (RFC 7489) https://help.mail.ru/mail-help/postmaster/dmarc
DSN generated by: AM6PR01MB5557.eurprd01.prod.exchangelabs.com
Remote server: mxs.mail.ru

As if in a letter, everything is logically indicated what the problem is, etc., in the DKIM check. But the fact is that all SPF and DKIM records are configured correctly and have not changed. Those. no changes have been made to the DNS for years. And the format entries: _DMARC.MYDOMAIN.COM 1 Hour TXT "v=DMARC1; p=none" are present and have not changed.

When you run the test from the soft ones, the following is issued:



PS Of course, I wrote in support of the soft ones, but there is a heavy load and answers are given once a week, if not later.

UPD:
Checking mail server

SPF record found: "v=spf1 include:spf.protection.outlook.com -all"
MX record found: donbiotech-com.mail.protection.outlook.com (priority 0)
DNS round-robing configuration with multiple mail servers
Only one MX record found.
Mail server donbiotech-com.mail.protection.outlook.com [104.47.10.36] priority 0
Mail server 104.47.10.36 responded to port 25
<= 220 DB5EUR03FT005.mail.protection.outlook.com Microsoft ESMTP MAIL Service ready at Thu, 14 May 2020 07:01:50 +0000
=> HELO mailvalid.nettools.ru
<= 250 DB5EUR03FT005.mail.protection.outlook.com Hello [95.216.150.141]
=> MAIL FROM:
<= 250 2.1.0 Sender OK
=> RCPT TO:
<= 250 2.1.5 Recipient OK
The mail server is available.
Mail server donbiotech-com.mail.protection.outlook.com [104.47.8.36] priority 0
Mail server 104.47.8.36 responded on port 25
<= 220 AM5EUR03FT062.mail.protection.outlook.com Microsoft ESMTP MAIL Service ready at Thu, 14 May 2020 07:01:51 +0000
=> HELO mailvalid.nettools.ru
<= 250 AM5EUR03FT062.mail.protection.outlook.com Hello [95.216.150.141]
=> MAIL FROM:
<= 250 2.1.0 Sender OK
=> RCPT TO:
<= 250 2.1.5 Recipient OK
Mail server available.
***Ok. All mail servers accept messages. ***

Answer 1

Apparently, the include:spf.protection.outlook.com parameter has been added to the SPF records, and the TXT record on the outlook.com subdomain has already been removed for some reason, as a result of which the SPF gives an error
No, I made a mistake, 2whois.ru did not see record on a subdomain, and nslookup and other services see. As an option, something was updated and the information did not have time to spread over the Internet