We have a domain mecart.com which is handled by Cloudflare. When an email is sent to a Microsoft email client (outlook, hotmail, etc.) and contains either mecart.com or www.mercart.com in its content, the email is tagged as spam automatically.
Here’s the error we generally get:
Message was deferred due to Suspicious (Nameserver for www.mecart.com:dee.ns.cloudflare.com)
I doubt it has anything to do with Cloudflare, but I wondered if anyone had ever raised a similar issue.