backlist smtp query - virus/trojan/something

[cava83]

Hi,

Been blacklisted.

NAT firewall.

One external IP.

Blacklisted by 4 separate companies.

Thus some of our clients not receiving our emails.

Running exchange on one server.

I have modified the firewall configuration as follows,

allowed port 25 to exchange server
deny port 25 to all workstations.

------------------------------------------

I am trying to test if this is done correctly, but can't receive external emails due to the blacklists.

How can I check if the rule is working ok........

Suggestions?

 

[cava83]

ok, telnet external ip port 25......

cool, that works.

 

[cava83]

ok, not getting a message saying

550 5.7.1 unable to relay for .............

(also checking out google, think this might be handy for someone if they did a search on here)