Clarifying, since this question comes up from time to time:
Also note that only the initial sender can do this. If mail goes A->B->C, A can downgrade if the A->B hop can't do EAI, but B cannot if B->C can't
Is this a MUST or a SHOULD (recognizing that RFC-style SHOULD is still very firm)?
/marksv
-----Original Message-----
From: ua-eai-bounces@icann.org [mailto:ua-eai-bounces@icann.org] On Behalf Of John Levine
Sent: Saturday, November 4, 2017 7:21 PM
To: Don Hollander <don.hollander@icann.org>
Cc: ua-eai@icann.org
Subject: Re: [UA-EAI] Thoughts on Downgrading
On Fri, 3 Nov 2017, Don Hollander wrote:
> The UASG will (after further consultation) include the following as a Good Practice (not best practice) guide for Downgrading:
>
> - The EAI Mailbox provider establishes an EAI address and an ASCII alias when the mailbox is set up.
>
> - The ASCII alias will have a display name equal to the EAI Address.
>
> - When a non-EAI compliant mail system is encountered, the EAI MTA will revert with the ASCII alias and Display Name.
>
> - The ASCII Alias should not default to a Punycode conversion of the mailbox name because bi-directional equivalence cannot be guaranteed.
Also note that only the initial sender can do this. If mail goes A->B->C, A can downgrade if the A->B hop can't do EAI, but B cannot if B->C can't.
Regards,
John Levine, john.levine@standcore.com
Standcore LLC
_______________________________________________
UA-EAI mailing list