SMTPUTF8 support

[John Fawcett]

On 06/04/2019 11:34, André Rodier via dovecot wrote:
> On Sat, 2019-04-06 at 11:19 +0200, John Fawcett via dovecot wrote:
>> On 06/04/2019 10:07, André Rodier via dovecot wrote:
>>> On 05/04/2019 08:57, David Bürgin via dovecot wrote:
>>>> André, are you quite sure you have it working?
>>>>
>>>> In this thread someone from Open-Xchange stated that no, Dovecot doesn’t
>>>> have SMTPUTF8 support implemented, and the same response was given by
>>>> another Dovecot developer last September (it ‘is being considered’ was
>>>> the answer then, see
>>>> https://dovecot.org/pipermail/dovecot/2018-September/112887.html).
>>>>
>>>> I am using LMTP to deliver mail to Dovecot from Postfix, and delivery
>>>> fails with Postfix reporting: ‘SMTPUTF8 is required, but was not offered
>>>> by host mail.my.org[private/dovecot-lmtp]’. I doubt that this can work
>>>> without a change in Dovecot LMTP.
>>>>
>>>> Anyway, I am also interested in SMTPUTF8 support, so +1 from me!
>>>>
>>>>
>>> Hello David et al,
>>>
>>> I have it working with my set up, and I confirm it is not easy.
>>>
>>> If I limit the stack to OpenLDAP, Postfix and Dovecot to their
>>> simplest configuration, it is relatively easy, even with slightly
>>> outdated software in Debian Stretch. 
>> I think you are confusing acceptance of UTF8 in the localpart of the
>> email address (which if I remember correctly worked in the 2.2 branch)
>> with SMTPUTF8 support. As mentioned in the thread above Dovecot does not
>> as yet support SMTPUTF8. Support for SMTPUTF8 would mean among other
>> things changing the source code of Dovecot so that it announces the
>> SMTPUTF8 key word to the upstream MTA.
>>
>> John
> Hello John,
>
> You are probably right.
>
> I am not well aware of the low level details and the terminology.
>
> I confess I am mostly interested in the proper reception of the emails
> with accentuated user names, which is already sometimes difficult to
> achieve.
>
> Is there any link where I can learn the communication rules between
> Dovecot and Postfix and the SMTPUTF8 standard ?
>
> Kind regards,
> André
>
André

Daniel Lange has posted some links to this topic from Postfix and
earlier discussions on the mailing list.

Postfix has this SMTPUTF8 documentation:

http://www.postfix.org/SMTPUTF8_README.html

On that page you can also find links to the relevant standards including
SMTPUTF8 standard.

John