do you want to issue a RFC that bans search lists?
Personally, I think search lists are a mistake and don't use them.
You're in good company. It's hard to find a modern mail system that allows abbreviated domain names in addresses. I just checked the mail at AOL, Yahoo, Gmail, and Hotmail, and the one at Tucows which is used by a lot of large corporate mail systems, and none of them will let you send a message to an address like foo@bar. Note that Yahoo and Hotmail each handle mail for many large ISPs. There's a lot of advice that made sense in 1989 which is irrelevant now. Programming around mail systems that rewrite partially qualified addresses is in that category. It may not be possible for people to send mail to addresses like n@ai, but that's a very different problem from it going to the wrong place. R's, John