< My proposal uses a type (ii) approach, but it has no problem with quoting
< conventions. Take my own name as an example. I admit that it's
< theoretically possible that the local-part
< can be used by someone who wants exactly this sequence of ASCII
< characters. Such a person will have to live with the fact that his
< address will be displayed with an a-umlaut instead of "*5A'" for users
< with modern mail programs. Or his postmaster will have to rethink his
< principles for forming cryptic mailbox names. There is no need for
< quoting conventions to allow displaying or writing addresses with "real"
< "*" characters, because such addresses are _identical_ to the
< corresponding addresses with non-ASCII characters.
< I don't think that this is a big practical problem. Asterisks are very
< rare in local-parts. And there is no natural reason to use them.
One note of warning about whatever encoding scheme is devised:
Most unix mail systems prohibit the following set of characters in mail names
Some prevent even more characters.
These characters are all special to the shell and could potentially be used
to create a security hole.