I use postfix to relay mail to 3rd party SMTP and never sent out email directly, and of course I never receive email.
So If I set myhostname / mydestination to sth like fake.mydomain.com, which mydomain.com is valid domain, but
- fake.mydomain.com record does not exist
- the IP of machine does not have PTR point back to fake.mydomain.com
Are there any drawbacks in the above settings?