Mark Andrews <marka@xxxxxxx> wrote: > > Apples mail client is broken [IPv6:2001:df9::4015:1430:8367:2073:5d0] > is not legal according to both RFC 5321 and RFC 2821 which is all > that applies here. I was until today unaware how strong the feelings are on this "one-or-more" vs. "two-or-more" issue. I do not expect to change anybody's mind. :^( But I do object to calling that EHLO string "not legal". The 5321 reference names RFC 4291 as the source of address syntax (even if it gives BNF which says "two or more" if you delve deeply enough). RFC 4921 is clear about saying "one or more". The Errata posted against it claiming it should say "two or more" have been rejected. It is silly to argue under these conditions that Apple's EHLO string is "not legal". BTW, RFC 5321 still contains the language about " if the verification fails, the server MUST NOT refuse to accept a " message on that basis. so IMHO enforcing any particular interpretation of what an IPv6 address literal should look like is double-plus-ungood. ==== To the casual observer, it looks as if RFC 4291 relaxed a previous "two or more" requirement, but there are folks who don't want to accept that relaxing. One can accept the idea that this relaxing has failed, yet still observe "liberal in what you accept" as trumping it. I truly wish the folks in the "two or more" camp would do so! -- John Leslie <john@xxxxxxx>