I think that this function (${utf8_localpart_to_alabel:str}) is chosen when it is sent to non-EAI MTA. It is its implementor's choice, a kind of downgrading.
 
 
if the destination is eai-ready, it will follow EAI RFCs.
 
--------------------------------------------------------------------
 
The main configuration option smtputf8_advertise_hosts specifies a host list. If this matches the sending host and accept_8bitmime is true (the default) then the ESMTP option SMTPUTF8 will be advertised.

If the sender specifies the SMTPUTF8 option on a MAIL command international handling for the message is enabled and the expansion variable $message_smtputf8 will have value TRUE.

The option allow_utf8_domains is set to true for this message. All DNS lookups are converted to a-label form whatever the setting of allow_utf8_domainswhen Exim is built with SUPPORT_I18N.

Both localparts and domain are maintained as the original UTF-8 form internally; any comparison or regular-expression use will require appropriate care. Filenames created, eg. by the appendfile transport, will have UTF-8 names.

-----------------------------------------------------------
 
Jiankang Yao
 
From: Don Hollander
Date: 2016-11-07 10:40
To: yaojk
CC: ua-eai@icann.org
Subject: Re: EXIM ready for EAI Re: [UA-EAI] Publication of EAI Providers

Yao,

 

${utf8_localpart_to_alabel:str}

 

What is the conversion that is done here?  Is it a punycode conversion or some other conversion?   So far the applications that I’m seeing are doing punyode conversions to the mailbox name.

 

Don

 

From: Jiankang Yao <yaojk@cnnic.cn>
Reply-To: yaojk <yaojk@cnnic.cn>
Date: Monday, 7 November 2016 at 3:02 PM
To: Don Hollander <don.hollander@icann.org>
Cc: "ua-eai@icann.org" <ua-eai@icann.org>
Subject: EXIM ready for EAI Re: [UA-EAI] Publication of EAI Providers

 

 

 

Based on the following message,

http://www.exim.org/exim-html-current/doc/html/spec_html/ch-internationalisation.html[exim.org]

Exim is ready for EAI too.

 

 

http://exim.org/[exim.org]

 

 

 

Jiankang Yao

 

Date: 2016-11-06 23:27

Subject: [UA-EAI] Publication of EAI Providers

Dear EAI Folks:

 

I’ve heard several requests to publish a list of contacts of people/organisations that are providing EAI ready software or services.

 

I have compiled an informal list.

 

•Microsoft

•Google

•Apple

•Yandex (Russia)

•Coremail (China)

•XgenPlus (India)

•Throughway (Thailand)

•SaudiNic

•OpenFind (Taiwan)

•Horde (USA)

•PostFix (Global)

•Afilias

 

These are folks who either have produced a production product and/or are working to make their systems truly EAI Ready.

 

My plan is to have a table like:

 

Product; web address; Service (Web based); Server; Client (Mac, Windows, Linux, IOS, Android); Contact Name (what do you think of this?)

Outlook2016 for PC; Microsoft.com[microsoft.com]; Client (Windows)

 

Etc

 

If you would like to be included in such a published, please let me know and provide me with the information.

 

I think that there’s keen interest in some communities to have a such a list so that they can get email in their own languages working.

 

Don

 

Don Hollander

Universal Acceptance Steering Group

Skype: don_hollander