There are many automated bots/scripts on the web who like to hunt down "contact us" pages and attempt to send out spam messages from them. Probid is not immune from these attacks, and at some point, if you have not already received these types of messages, then you will.

This modification will inject the sending users IP address into the message and you can then use the IP address to ban them from your server, hence eliminating the problem right from the get go.

Very simple mod.