We are having an issue at my current job. Our ISP has reported to us that we have been reported as a Spamming site. We have had this issue in the past and the way we found out which machine was spamming was by turning off port 25. The person that turned the port off used software he had in order to do it and of course he took the software with him when he left. I need to know the commands to turn off port 25 and turn it back on again. Please help.