All mail goes to spam

[ashok]

WARNING: Found mail servers with inconsistent reverse DNS entries. You should fix them if you are using those servers to send email.
Server                           IP                                                PTR (Reverse)                                  IPs
360shutters.in. 104.238.182.138 <-------------------> 104.238.182.138.panel.360shutters.in.   ?

All mail servers should have a reverse DNS (PTR) entry for each IP address (RFC 1912). Missing reverse DNS entries will make many mail servers to reject your e-mails or mark them as SPAM.

All IP's reverse DNS entries should resolve back to IP address (IP → PTR → IP). Many mail servers are configured to reject e-mails from IPs with inconsistent reverse DNS configuration.

Thanks , I'm new to this could you please guide to setup the Rdns properly?