I started self hosting in 2017. (With a fresh domain. I'm the only user.) My sever closes the incoming connection if it doesn't has a rDNS or the HELO doesn't m

I started self hosting in 2017. (With a fresh domain. I'm the only user.) My sever closes the incoming connection if it doesn't has a rDNS or the HELO doesn't match the rDNS. Apart from that I have no anti spam measures! Friends and family have my firstname.lastname@domain address. Websites and companies get a <random>@domain address. So far I have only reserved 3 spam mails. Two times they got the address from a public mailing list I participated. One time it was from a webshop that sold or leaked my address.