[devjam]

Nor does it accept "+" characters in the email address localpart, as allowed in RFC822 (1982).

[CameronNemo]

I recently learned that single words are considered valid email addresses... e.g. "foo" or "root".

[Cyph0n]

Isn’t that how mail gets routed to local user mailboxes?

[CameronNemo]

Yes, exactly. I just never expected an email parser to recognize those cases.