Hi I got the big problem in my exchange server that somebody is using one of our email and sending the junk mail. So that, exchange server is already block and when I check with Queue Viewer there got a lot of message as I remember over 200,000 :( Now, I have been clean out all those message. But I don't have such knowledge how to prevent it if later come this problem again. I am using Exchange server 2007 and got statics IP Address and using Firebox. Thank you so much for your useful advice. With RegardsProgramming is Art.

Hello Soee, Is these spam messages from user in your domain or other domains? If this is from user in your domain, use message tracking to find which account send the junk mail. If these emails are from external, go to check the configuration on your Exchange Server, make sure you are not use open relay. Thanks, EvanEvan Liu TechNet Community Support

Hello Soee, Is these spam messages from user in your domain or other domains? If this is from user in your domain, use message tracking to find which account send the junk mail. If these emails are from external, go to check the configuration on your Exchange Server, make sure you are not use open relay. Thanks, EvanEvan Liu TechNet Community Support