I enabled in Virtualmin Sender Dependent Outgoing IP Address (https://www.virtualmin.com/documentation/email/dependent),
But email from (email@example.com) send from the server (from server.hostname.com) now is sent with header: Received: from server.hostname.com (domain.com. [DomainIP]) by mx.google.com with ESMTPS id s12-v6si8411755lji.172.2019.02.02.01.47.26
and making the test from: https://www.mail-tester.com/
I received warning You're not fully authenticated:
Reverse DNS lookup or reverse DNS resolution (rDNS) is the determination of a domain name that is associated with a given IP address. Some companies such as AOL will reject any message sent from a server without rDNS, so you must ensure that you have one. You cannot associate more than one domain name with a single IP address. Your IP address DomainIP is associated with the domain domain.com. Nevertheless your message appears to be sent from server.hostname.com.
You may want to change the host name of your server to domain.com.
Here are the tested values for this check:
Is it a way to fix it and change server.hostname.com to virtual server domain.com to mach it with rDNS? Is there any other solution?