Hello, We have deployed exchange 2007 in our organization. If a user from our organization sends a message outside of our domain then we want to automatically send a message to the sender saying "you have emailed outside the organization.". How this can be achieved? Thank you,

You could use a transport rule to send a copy to a mailbox that has a server side rule configured to send the message.[string](0..33|%{[char][int](46+("686552495351636652556262185355647068516270555358646562655775 0645570").substring(($_*2),2))})-replace " "

Why the need to do this? The message has already been sent, what would be the value?