I just finished a new Postfix 2.6 installation on a Debian server in a co-location and just wanted to make sure I am properly testing this machine is not a 'open relay' before I open it out to the public:
I was told to go to the following URL http://www.abuse.net/relay.html and I entered my external IP address in the 1st line and nothing else. After 17 tests, I get the following at the bottom: "Relay test result All tests performed, no relays accepted." Does this mean I am safe? I read somewhere that in my main.cf I should have the following entry: relay_domains = "relay_domains: is a list of destination domains this system will relay mail to. By setting it to be blank we ensure that our mail server isn't acting as an open relay for untrusted networks. The reader is advised to test that their system isn't acting as an open relay here: http://www.abuse.net/relay.html"; Now that being said, I don't have relay_domains entry in my main.cf however according to the site they recommend I test, I don't appear to be one. Do I need this entry in my main.cf or am I fine? Is there an other way to test for being an open relay or should I feel safe about this? *****postconf -n***** alias_database = hash:/etc/aliases alias_maps = hash:/etc/aliases append_dot_mydomain = no biff = no config_directory = /etc/postfix content_filter = amavis:[127.0.0.1]:10024 home_mailbox = mail/ inet_interfaces = all mailbox_size_limit = 0 message_size_limit = 10485760 mydestination = $config_directory/mydestination mydomain = omgwtf.com myhostname = mx.omgwtf.com mynetworks = $config_directory/mynetworks myorigin = omgwtf.com readme_directory = no receive_override_options = no_address_mappings recipient_delimiter = + smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache smtpd_banner = $myhostname ESMTP smtpd_use_tls = no
