Why?

Well because there is no need for brothers to talk to sisters unless it is essential.


Now see, that is basically one of the reasons why super mods have the right to check the P.M's between brothers/sisters..to make sure everything goes in accordance to the Shariah law as sister Labibah has stated earlier.



Now if a sister for some reason perfers to give the message to a brother via a mod then by all means she is enable to do so.



Infact, this is one of the better choices then directly communicating to a brother, in my opinon.