also mention the connection notes in the POD
added X-HELO header to message added timeout option quieted down debug logging
helo - validate a HELO message delivered from a connecting host. Includes the following tests: is_in_badhelo invalid_localhost is_plain_ip is_address_literal [N.N.N.N] is_forged_literal is_not_fqdn no_forward_dns no_reverse_dns no_matching_dns