MTA-STS failure

When emails are sent to my email address on my self-hosted email server, from Microsoft (Office 365 or Exchange), the MTA-STS policy of my self-hosted mailserver is not applied due to the error listed below.

I have tested my MTA-STS policy using several DMARC-providers, eg 'Mailhardener' etc., and they all find the MTA-STS policy url is reachable and the policy is valid.

This problem does not occur with incoming email from other email providers, eg Gmail.

There are no other email problems, eg. SPF, DKIM, DMARC etc.

Please help me solve this issue.

Error:

{"organization-name":"Microsoft Corporation","date-range":{"start-datetime":"2024-11-18T00:00:00Z","end-datetime":"2024-11-18T23:59:59Z"},"contact-info":"[email protected]","report-id":"133765181884122747+REDACTED","policies":[{"policy":{"policy-type":"sts","policy-domain":"REDACTED"},"summary":{"total-successful-session-count":0,"total-failure-session-count":2},"failure-details":[{"result-type":"sts-policy-fetch-error","failed-session-count":2}]}]}