I found the following web page by using Google.
http://www.computerhope.com/unix/umailx.htm
The interesting part is the carbon copy parameter. It says that if you want to carbon copy more than one person then you have to put the names in quotes. That may provide a clue to your situation.
On another note I can hardly believe that you would use that kiddie spelling in work. Your message "ur mailbox..." and "plz delete..." are incredibly immature and unprofessional.