Re-check my post: $Email::Valid::Resolver = 1 was incorrect. As far as I can tell $Email::Valid::Resolver->tcp_timeout($seconds) is correct, though doesn't seem strong enough. I apologize for the confusion.
What version of Email::Valid and Net::DNS are you using? Line 41 of Email::Valid in the version currently available on CPAN doesn't contain code that should trigger that message.