Re: Select all invalid e-mail addresses

On 10/20/05, Douglas McNaught <doug(at)mcnaught(dot)org> wrote:
>
> > It performs a MX-lookup, which IMHO is the best way to check for
> validity.
>
> But that's expensive and slow, and doesn't tell you whether the user
> part of the address is valid (and in general, there's no way to
> determine that short of actually sending a message). So what's the
> point?
>
> -Doug
>
>
That's why I think the better term for this is "well formed". "Validity" can
only be determined by sending to it, but you can tell if an address at least
conforms to the specs programmatically. In the end, when talking about a
"valid" address in this context, that is what most people are talking about.

The point is to weed out malformed email addresses, just like you would
enforce any other data formatting standards in other types of data.