I don't see how your proposed solution does what I requested. It doesn't do any canonicalization of quotes nor escapes. Yes, it eliminates comments. But your test considers jdoe@bla.com to be different from "jdoe"@bla.com, for example. Perhaps there are some other "tokens" I should be asking for instead?

Yes, I suppose I could go to the trouble of parsing RFC 2822 (except for not allowing abitrary nesting of comments and not allowing CFWS in many places) in order to throw away the parts I don't want and then reparse the other parts to do additional validation and canonicalization. I suspect that will be more code (not counting the code for the module) than the solution I've already written. And it won't allow for simple customization such as allowing /\.@/ as noted elsewhere.

The module almost does RFC 2822 but doesn't do a good job of practical validation of e-mail addresses typed in by external users. I don't see its contribution to my task being much of a "win".