* Carlos E. R.
I believe reject_unknown_sender_domain shouldn't do a reverse check, but a direct one. For example, if I send as "noname@doesnotexist.com", postfix should do a query, like the command "host doesnotexist.com". If it comes out as non existing, the domain was invented, not real. I think dyndns should work, because the name should resolve.
I have no-ip.org which is similar to dyndns and employe reject_unknown_sender_domain and do not *seem* to have any problem with any mail. I look at the logs every morning and see nothing amiss. I sometimes get 300-400 rejects for unknown_sender_domain and for "User unknown in local recipient table". It's just that much more that SpamAssassin does not have to filter/reject. I have also noticed that /etc/postfix/access does not seem to perform as expected, but header_checks *does*. postfix-2.2_20040616-1 -- Patrick Shanahan Registered Linux User #207535 http://wahoo.no-ip.org @ http://counter.li.org HOG # US1244711 Photo Album: http://wahoo.no-ip.org/photos