I remember that was the first thing I used to do on my mail servers, ever before DKIM etc. Why? I have no idea and I will never know. Is sending email via IPv6

I remember that was the first thing I used to do on my mail servers, ever before DKIM etc. Why? I have no idea and I will never know. Is sending email via IPv6 important to me? No. Is mail delivery important to me? Yes. Why is Google such a bad player in this field? Because in spite of having the biggest email network they don't want to allocate relevant resources to handle spammers properly. In other words, they are OK with false negatives, that is us. For this reason, I'm fine with this ugly workaround.