Postfix Relay Getting Spammed Bad -- But no open relay...
Hello everyone, im running a postfix server on CentOS 5. I have ports 143 and 25 open. 110 is closed because i use imap and squirrelmail. I get spammed all day long - Relay this message to this address -- alot of which go to taiwan. I saw an smtp block from yahoo because of these spam mails. I went to a testing site and it tried to relay mail off me and it couldnt. My question is, how come people can relay off me, but yet this website says im secure? How can i lock down the server and only allow internal connections (blackberry, squirrelmail hosted on same server).
Searches on the internet go into detailed multi-page long fixes that i dont understand. Is there a simpler way?