Most probably because your message did not pass the DMARC Authentication

To make sure go to

https://mxtoolbox.com/

Then so clear error

Info about the DMARC

DMARC Records are published via DNS as a text(TXT) record. They will let receiving servers know what they should do with non-aligned email received from your domain.

Domain-based Message Authentication, Reporting, and Conformance (DMARC) is a mechanism for improving mail handling by mail-receiving organizations

According to the rfc7489

https://tools.ietf.org/html/rfc7489

Domain-based Message Authentication, Reporting, and Conformance

(DMARC) is a scalable mechanism by which a mail-originating

organization can express domain-level policies and preferences for

message validation, disposition, and reporting, that a mail-receiving

organization can use to improve mail handling.

What is DMARC Authentication? And how it passed the test ?

It is simply two things SPF and DKIM

To pass DMARC authentication, a message must both Pass and Align for either SPF
or DKIM. Even if a message passed authentication for both SPF and DKIM, it could still fail DMARC authentication if one of them does not “align.” There are two ways to pass DMARC authentication:

SPF and DKIM

How to set it up and solve it ?

It only takes a few minutes to get started with DMARC and you’ll see immediate benefits. The first thing you need to do is add a simple DNS record to enable DMARC reporting. If you would like MxToolBox to handle your DMARC reporting for you, just add this simple text (TXT) record to your domain’s DNS.

Ref:

MXTOOLBOX:

https://mxtoolbox.com/problem/dmarc/dmarc-record-published?abt_id=AB-366&abt_var=Control&page=prob_dmarc&action=dmarc:lepide.com&showlogin=1&hidepitch=0&hidetoc=1&utm_expid=.Q03IJTZISU2ag-YCrxpRCA.1&utm_referrer=https%3A%2F%2Fmxtoolbox.com%2FSuperTool.aspx%3Faction%3Ddmarc%253alepide.com%26run%3Dtoolpage

RFC:

https://tools.ietf.org/html/rfc7489