Yeah basically, but it doesn't validate an email address (user@example.com), it validates say, the From: header of a MIME message, which could contain an email address, a phrase (like a first and last name) comments, and all sorts of dumb dumb ideas like having phrases that have embedded comments and phrases that look like email addresses but aren't and on and on and on. This RFC is a trainwreck and whoever wrote it should feel bad about themselves.