On 4/27/2015 8:10 AM, Viktor Dukhovni wrote: > ...The only acceptable alternative
> representation that comes to mind is a table of ascii-only addresses
> explicitly configured for senders in the MSA's local domains, that
> are accepted on the reverse path as valid addresses for these same
> senders. With that, you could encode sender addresses when forwarding
> ascii-only recipients to non-EAI systems (or sending email to
> recipients in the same domains for which ascii-only forms exist).
Viktor, I would not define the scheme that you describe as "encoding".
Instead, I see that as merely an example of a particular form of local
address aliasing. Aliasing, for whatever purpose, is a matter of purely
local concern. Using that definition, the prohibition against encoding
any local parts has no need of exceptions of any kind.