2/22    Can someone point me to an RFC that specifies which ascii characters
        are valid in email addresses?  I can't seem to find it in 2821 or
        2822.  -John
        \_ It's scattered around RFC 2822.  The actual definition of an email
           address (addr-spec) is section 3.4.1, but it refers to a lot of
           stuff from earlier in section 3.
                \_ Cool, thanks.  I noticed that a lot of online email
                   address parsers reject 'a+b@domain.com'--was just sort of
                   wondering whether there's anything they're "supposed" to
                   accept.  -John

           The upshot is that nearly any ASCII character is allowed if quoted
           properly, including whitespace and control characters.  The only
           thing you can't have at all is a NUL character -- and even that
           used to be permitted, so RFC 2822 still requires you to handle it
           properly.  Non-ASCII characters (anything above 127) are not
           allowed; RFC 2047 specifies the =?ISO-8859-1?Q?=E9?= syntax for
           encoding them.

           Of course, you may not want to send mail to anyone belligerent
           enough to have control characters in their email address.  --mconst
           \_ ooooh, sweet.  I never thought of that.  If I had control chars
              in my email address do you think that would avoid all spam?