Sending notes across the network to another users requires a few things, but the most important is being able to understand how networks work, especially in relation to security and routers.
If you are in your home, it would be almost impossible for a note to appear on your "friends" computer if they are behind a router or firewall. Most home computers are not hooked up directly onto the internet. They are usually behind routers and firewalls, and this is for security reasons.
If you are in a work environment, then all employees are on the same lan and most have static IP addresses. You can easily send a note to a fellow employee on the network (LAN) provided you know either their IP address or their computer name. iQ-Notes can handle both IP address or computer name.
First, make sure the firewall has the postit.exe program in the firewall exceptions and/or the port you are going to use for sending notes. Then, enter the IP address of the fellow computer you wish to send the note to or the computer name on the network. I recommend using computer name because if the computer is not using a static IP and they reboot tomorrow, then the IP address may change, but the computer name is always going to be the same.
If you want to send notes to a friend outside the LAN, it will be impossible unless you understand port forwarding with your router. It can be done, so simply read up on your router manufacturer website about port forwarding and allowing the router to see the request coming in, and then forward it to the right computer device inside the home. If you are within the same LAN or environment, try using the computer name.
The computer name can be found by right-clicking on My Computer and then going to Properties.