🚀 go-pugleaf

In <aynnmf.356@wang.com> fitz@wang.com (Tom Fitzgerald) writes:

>> On 18 Dec 90 14:22:13 GMT, lws@comm.wang.com (Lyle Seaman) said:
>> lws> It's worth noting that the world is still pretty split about how to
>> lws> handle the % hack, with some sites giving it precedence over ! and
>> lws> others not.  This is an unfortunate situation.  The only solution
>> lws> is to avoid mixing % and !  if at all possible.

>pcg@cs.aber.ac.uk (Piercarlo Grandi) writes:
>>
>> Example: a!b!c%d.e.f
>>     on a UUCP machine: route this to the 'b' site which is a
>>     neighbour of the 'a' site, and on 'b' deliver mail to
>>     'c%d.e.f'.

>This is excellent advice, and I agree with it 100%, but bear in mind that
>it contradicts RFC1123, which says that the example should be passed to
>d.e.f by whatever means, and d.e.f should decide what to do with a!b!c.
>(Basically the recommendation is that ! binds tighter than %).

>Many machines (including UUNET) disobey RFC1123 in this respect, and get
>mail delivered.  Many other machines comply with RFC1123, and generally
>lose mail from UUCP sites that has %'s in the destination address.

To quote from section 5.2.16 of RFC1123:

	It is suggested that "%" have lower precedence than any other
	routing operator (e.g., "!") hidden in the local-part; for
	example, "a!b%c" would be interpreted as "(a!b)%c".

To me this seems a contradiction.  Surely if "%" has lower precedence
than "!" then "a!b%c" should be interpreted as "a!(b%c)"!
Assuming this, sites such as uunet are doing "the right thing".  To me
it seems the sensible way of doing things.

No wonder so many sites "don't comply" with RFC1123 in this respect.

Mind you, I have a mail redirect going through a host which interprets
"%" above "!", and the mail feed for a domain of ~20 machines would break
if they suddenly started doing "the right thing".

Is this a typo in the RFC, or am I totally deranged?
_____________________________________________________________________________
David Burren [Athos]                          Email: david@bacchus.esa.oz.au
Software Development Engineer                 Phone: +61 3 819 4554
Expert Solutions Australia, Hawthorn, VIC