Telnet to yourmailserver at port 25 and issue all the following commands:

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telnet hostname/ip 25

helo client.server.com

mail from: xxx@somedomain.com

rcpt to: yyy@somedomain.com

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If you are getting the error “554 : Relay access denied” then the server is not an open Relay

If not Just pass the command “DATA” sfter the recipient and then enter the message ending with a period ie : “.”

If you get the reply “SUCCESS Relay Accepted – final response code 550″

Then as you feared your server is subjected to open relay and if not enjoy………. It is not

I hope your server is not open relay supporting, but if it is so, as it is a Cpanel Server you can stop it normally using the below scripts

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/scripts/fixrelayd

/etc/rc.d/init.d/antirelayd restart

service exim restart

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