No, it’s the other way around. You can’t receive mail from standards-compliant servers if you don’t follow the standard. What the point is of the standard requ

No, it’s the other way around. You can’t receive mail from standards-compliant servers if you don’t follow the standard. What the point is of the standard requiring you to use a name instead of an IP address is a reasonable question but not the same question as whether you should follow the standards. Note this is a standard made by people who knew what they were doing and it has stood for 35 years. There’s always room for improvement but it would be a bit silly to think you can just handwave it away with arguments you can come up with in a few seconds. There is bound to be a catch. In this case the catch of course is that there are more address types than IPv4 addresses, so the system requires you to specify what kind of address you are talking about. The mechanism for that is the A record, which only holds IPv4 addresses.