||E-mail validation class
||E-mail address validation class
Determine if a given e-mail address is valid.
||By Manuel Lemos
||Avoid checking agains hostnames that do not resolve to any IP address.
Added support to lookup also the ip address and the reverse of the servers
in the invalid list.
Fixed the matching of server domains that need to be resolved to match the
IP address of the MX server.
Added support to resolve invalid mail server names before comparing with
the server IP address.
Fixed the validation of invalid domains and e-mail servers.
Added a function to pre-validate an address by checking agains domain, user
and servers white and black lists.