>>
https://bugs.exim.org/show_bug.cgi?id=2730
> It seems you're referring to:
>
> https://tools.ietf.org/html/rfc6531#section-3.7.3
>
> When an SMTPUTF8-aware SMTP server adds a trace field to a message
> that was or will be transmitted with the SMTPUTF8 parameter included
> in the MAIL commands, that server SHOULD use the U-label form for
> internationalized domain names in the new trace field.
>
> Which appears to be concerned primarily with the "Return-Path:" header,
No, what I was testing was the domain names in Received headers, the FROM
and BY clauses. Discussions in the IETF have told us that it is a
religious issue whether you consider Return-Path to be a trace field.
> In that context, use of non-ASCII domain forms may needlessly break
> message delivery, if the mailstore does not support non-ASCII headers,
> and UTF8 would not otherwise appear in the message headers.
If UTF8 would not otherwise appear in the message headers, why would the
mail be sent as SMTPUTF8? That doesn't strike me as a very strong
argument.
Like I said, it's not a huge bug, but the spec is clear enough.
R's,
John
