@domi@donotsta.re@dam@0.9.2.e164.arpa at my group we also have a e164.arpa subdomain. it's part of the E.164 standard. thing is, some countries have let the DNS servers' domains expire because it's not really used these days... and nothing's stopping you from snatching them and serving your own.
@domi@donotsta.re@dam@0.9.2.e164.arpa in the case of 0.9.2.e164.arpa it's pointing at ns.enum.org.uk and ns6.icb.co.uk... enum.org.uk was expired and @dam@0.9.2.e164.arpa snatched it. ns6.icb.co.uk doesn't resolve at all. you can guess what happened next.
(actually we had that domain too, i guess we let it expire accidentally, oops)