Intuit Mailchimp support has informed us that we are not aligned with Google/Yahoo regulations because our DMARC policy is set to p=reject. And to be aligned, we need to have a p=none setting. This misalignment is the reason our emails are being rejected by Gmail.com email addresses.

However, there is an issue: Mailchimp is sending 100% of our emails as non-authenticated, even though we have DKIM signatures implemented, and the email header confirms this.

The issue appeared suddenly, and we are 100% sure it is on their end. I don't understand how to address this with them, especially when they claim the problem lies with our p=reject setting.