> If someone's valid email address > [*\"32f2@13.31.43.11 > they are up to no good Well, that one in particular, perhaps — but what about "sam & jill"@ourfam

> If someone's valid email address > [*\"32f2@13.31.43.11 > they are up to no good Well, that one in particular, perhaps — but what about "sam & jill"@ourfamily.invalid? What about john(for sly010)@nowhere.invalid? > Also, according to the standard email addresses supposed to be case sensitive, since the username part refers to a unix user and unix is case sensitive. The local-part doesn't refer to a 'Unix user'; it is what it says on the tin: the local part. It's up to the receiving server to determine what it wants to do with case. It's the duty of other servers to preserve the email address as transmitted. > I work with a lot of email address lists originally collected on paper and of course noone knows that. So as bad as it sounds, part of my sanitation process is to lowercase everything. I might use the email address as given, and if that bounces try lowercasing. I don't know of anywhere that has case-sensitive names, but it's conceivable.