Re: A couple of comments on the open issues...

[ This thread is about subaddressing ]

At 8:12 PM -0500 2/14/03, John C Klensin wrote:
>There are no standards at all for interpreting the local part. The 
>standard is "no one but the delivery MTA can try to interpret the 
>local part in any way".

Exactly right.

>Getting internationalization at the cost of reduced functionality 
>for anyone or anything that is now doing something that conforms 
>should be considered only if it is the only way.  It isn't.

Fully agree.

The purpose of the discussion about making IMAA subaddress-aware is 
to make is so that the delivery MTA can do something based on the 
subaddresses. But IMAA doesn't need to be subaddress-aware for that 
to happen. MTAs that do things with subaddresses already have a 
processing step for how to parse a full address and what to do after 
parsing. Those processes could simply have a ToUnicode step added 
before the processing step, at which point the subaddress delimiters 
appear.

If we try to make IMAA subaddress-aware, we inherently restrict the 
characters that can be used as delimiters for subaddress. If we don't 
make IMAA subaddress-aware, there is no restriction, and current 
systems work exactly the way they do now if they add the ToUnicode 
step before subaddress processing.

We can do a lot of damage and make a lot of restrictions trying to be 
smart here. Let's instead go back to IETF first principles and let 
the end systems do the thinking.

--Paul Hoffman, Director
--Internet Mail Consortium