Re: [ietf-smtp] How wrong is this EAI implementation

John Levine <johnl@taugh.com> Sun, 21 June 2020 14:53 UTC

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From: "John Levine" <johnl@taugh.com>
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Subject: Re: [ietf-smtp] How wrong is this EAI implementation
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In article <kzlyExy/3YBZVUSNURxDqMLjYwWYAVGpn6yogCjhITg=.sha-256@antelope.email> you write:
>I note that there is no explicit requirement to treat incoming a-labels 
>as equivalent with u-labels anywhere in the EAI RFCs. Which means that 
>you can convert labels before sending, but you cannot rely on the 
>receiver to interpret the result as desired.

I don't think that 5321 requires that bob@example.com and bob@EXAMPLE.COM
be treated the same, either.

Beyond some point, you can't force people to be reasonable.

In the particular case I mentioned, my MTA is Courier which treats
A-labels and U-labels equivalently in mail addresses, but not in
identifiers for authentication.  It was easy enough to add both versions
to the identifer table, but I think I'm going to send a bug report to
roundcube.