Re: Mandatory From field, anonymity, and hacks

On Thu, 29 Jul 2004 22:51:35 -0400, Bruce Lilly <blilly(_at_)erols(_dot_)com> 
wrote:

> Charles Lindsey wrote:
>
> > Indeed, but "invalid DNS names" means, er, "invalid DNS names", and
> > "other  similar uses" should cover most other applications.
> No. Printed examples place no load on DNS, testing has negligible
> impact. Widespread use in messaging would place a large load on DNS.
I already explained that in reply to Keith. Naturally, agents that are  
minded to reply/followup to articles with .invalid TLDs in the from field  
need to check for the .invalid TLD. That should be obvious, and  
consequently the Usefor draft says 'Followup agents SHOULD NOT attempt to  
send email to any address ending in ".invalid"'.
> > And if you read further down in RFC 2606 (I don't have the exact words
> > in  front of me), you will see that it is recommended for use
> I do have the text, and there is no such "recommend[ation]".
It says

      ".invalid" is intended for use in online construction of domain
      names that are sure to be invalid and which it is obvious at a
      glance are invalid.

which is pretty much what I said (and you snipped), and is exactly the  
intent of what is currently proposed in the Usefor draft.
> > > Well, I might be inclined to prefer using a fixed, guaranteed  
> > > black-hole
> > > valid address if somebody wants to set one up...
> >
> > It doesn't need setting up. The TLD ".invalid" already has the required
> > property
> Wrong. There is a huge difference between NXDOMAIN and an MX record that
> points to a server that discards messages.
> > No, I meant exactly what I said. If it is guaranteed, by IANA
> > registtration, that ".invalid" will never resolve, then agents need not
> > bother to try it.
> You have missed the point.  Evidently you haven't looked at RFC
> 3696.
I have now looked at RFC 3696, and what Usefor proposes seems entirely  
consistent with same. Essentially, it says that if you intend user agents  
to check for and act upon particular TLDs, then you need to be pretty sure  
that  your filtering is fully consistent with the relevant published  
specifications. A registration with IANA that a given TLD will _never_  
resolve to anything seems as clear in that regard as one can get.

--
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