Re: [DNSOP] [off-topic even more than non-IETF work] was Re: [Ext] name folding, was draft-ietf-dnsop-alt-tld-17

[John Levine <[e-mail]>]

It appears that Paul Wouters  <[e-mail]> said:
>On Wed, 24 Aug 2022, John Levine wrote:
>
>> Many people believe that but it's not entirely true.
>>
>> While most mail systems treat upper and lower case in local parts the same,
>> I have occasionally seen setups where you can send mail to [e-mail]
>> and other capitalizations bounce.
>
>In my 30 years of SMTP email I have never run into this. "The expectation
>of the many, outweigh the expectation of the one" :)

If you don't spend much time writing or maintaining mail software,
it's not surprising that you wouldn't run into edge cases. You
wouldn't believe some of the strange stuff that Ned Freed described in
actual running systems at large companies that ran his mail software.

To look at it another way, in all the time I've been using the DNS
I've never run into an OPENPGPKEY record or turned on
edns-tcp-keepalive, but I have no objection to other people using
them.

>> Hence I would tell people that if they make their names case sensitive
>> they are likely to be sorry, but I wouldn't try to enforce anything.
>
>That sounds like a draft that could contain a SHOULD NOT or even a MUST
>NOT. Already better than the current status quo of an IETF requirement
>being completely obsoleted by real world deployments of billions of mail
>boxes.

After further consideration, I think we should stay completely out of
the business of offering advice on how to write things that look
like the DNS but are not the DNS. We have plenty of work already on
the thing that actually is the DNS.

R's,
John