In your previous mail you wrote: Specifically, the problem Dave encountered earlier was that the ietf mail server was rejecting mail without reverse dns, and since the ietf mail server and the mipassoc.org/dkim.org/bbiw.net mail servers all had ip6 addresses, and ip6 is used preferentially, and I hadn't set up reverse dns, they were dropping all mail. I fixed that, and things started working. => I had the same problem (IPv6, no reverse, dropped messages), I asked the IETF postmaster to fix it and it was (quickly, thanks) fixed. But I still believe this is a bad idea to check IPv6 reverse DNS, I reverved this topics for the plenary at Dublin but as you open it... PS -- I'm not sure this will actually make it to the ietf list :-) ... => according to Glen via RT (RT is a well known bug ticket system): "This check is in place at the direction of the IETF community, and has been discussed and debated at length." so as the IETF community voice is this list IMHO it is appropriate (until some authority delegates the issue to the v6ops WG?). Thanks Francis.Dupont@xxxxxxxxxx _______________________________________________ Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf