Artifact Signing: Email validation failed during organization identity validation — Urgent review needed

Problem description

I am experiencing an issue with the email verification step during my organization identity validation for Trusted Signing - Preview in West Europe. Despite successful manual email delivery tests to my domain addresses, the validation was rejected with the message 'Email validation failed.' I am seeking clarification on why the email verification was rejected despite evidence of email receipt.

Environment

Product: Trusted Signing - Preview; Region: West Europe; Scenario: Organization identity validation; Email setup: domain-based primary validation email routed through a third-party email-forwarding service.

What I've already tried

I manually tested email delivery to the primary validation address and another address on the same domain, confirming that both messages were received successfully through the current mail routing setup. I also reviewed available guidance on trusted signing and submitted a new validation request, which is currently in progress.

Current status

I am seeking assistance to understand why the validation was rejected despite successful email delivery tests and to determine the next steps for resolving this issue.