I know that most people know how much email addresses suck, but I found this message in Mutt while looking for something else, and I thought it was a nice illustration.
A user of Email::Valid writes:
I was doing some testing with Email::Valid, and I came across this:
$ perl -MEmail::Valid -e "print Email::Valid->address('dave@#%^&*$.com') ? 'yes' : 'no'"` yes $This prints "yes", and I don't understand why that address would be seen as valid. It doesn't seem to matter what characters are in the domain part of the address, it always gets marked as valid.
I replied:
Let's have a look!
dave@#%^&*$.comYou don't think this should be valid. Let's consult the RFC.
Section 6.1 says that an address must be
. That is: local-part "@" domainI'm guessing you don't dispute that "dave" is a valid local-part. A
must be: sub-domain *("." sub-domain)I'm also guessing you don't dispite that "com" is a valid sub- domain. So, is "#%^&*$"? Well, let's see...
sub-domain = domain-ref / domain-literal domain-literal = "[" *(dtext / quoted-pair) "]" domain-ref = atomThere are no square brackets, so there is no domain-literal involved. That means that if "#%^&*$" is a valid atom, it is also a valid domain-ref, and the address matches the addr-spec pattern.
The atom pattern is:
atom = 1*None of those characters are space or control characters. The specials are:
specials = "(" / ")" / "<" / ">" / "@" ; Must be in quoted- / "," / ";" / ":" / "\" / <"> ; string, to use / "." / "[" / "]"None of them are specials, either! Are you shocked? Don't be! RFC822 sucks!
I hope this helped. Good night! :)
Re:Strange domain names
rjbs on 2007-04-24T03:07:07
Right. In fact, since this email exchange took place, Email::Valid's check that a domain is valid has become more useful, and would reject this. The only default test is for a fqdn, which has lately come to mean a fqdn for a valid internet domain.
Still, the awful thing is that the address is valid according to 822, just not deliverable on this Earth's internet.
