so? there are lots of addresses which are valid syntax but
not valid because the domain is not defined or the IP
address (in the domain literal) does not exist or is not
assigned to a host.
I'm not sure I buy that reasoning. You seem to be saying that since it's
not possible to detect all invalid addresses syntactically that the ability
to trap some syntactically (or more than currently trapped) is irrelevant.
no, I'm saying that
- there is useful separation of function here between detecting syntax
errors and detecting addresses that are invalid for other reasons that
should not be discarded
- being able to detect that a few very-seldom-used addresses are
illegal by means of syntax is of infintesimal value
- trying to detect a significant number of invalid addresses by means
of syntax is likely to both increase errors (because there are more
things that can go wrong) and to impair the utility of email addresses
at some future date.
in other words, it's a fool's errand.
Keith