Hello; This may be easy for you guys, but for the life of me I can't figure it out. How do I block all outgoing traffic on a specific port but let through one computer on our local Lan? I have a mail server located on a specific IP and I want to allow outgoing traffic for that machine. I want to block port 25 on all other computers except the mail server. How do I do this? Thanks in advance for your help, I'm a newbie to security and firewall settings.