Email Routing Emails Marked as Spam

Hello,

I have one domain name with 3 email addresses forwarding a couple of emails per day (No more than 10 emails) and over the last weeks I noticed that Gmail marks them all as spam.

Is there any way to fix this issue? I had the same domain forwarding emails with another free provider for over a year and my emails were delivering fine.

Thanks.

Is that from Cloudflare?