I have tested and set a new instance based on AWS. We do not like to use Amazon Route 53 as our DNS service as we use CloudFlare.
They recommend assigning a reverse DNS record to the Elastic IP address we use to send email to third parties.
As it should be posted also any reverse DNS records that AWS needs to associate with the Elastic IP addresses how to set A record in this case due to security inside Cloudflare? Is this managed only by AWS or we can manage inside CloudFlare as we like to keep DNS records inside CloudFlare?