Why would net send work from DC, but not from workstation

I have group policy setting to turn o nthe messenger service for all of my
workstations: however ,if I run a net send command from my workstation, i
get the following error:

C:\Program Files\Support Tools>net send computername test
An error occurred while sending a message to COMPUTERNAME.

The message alias could not be found on the network.

More help is available by typing NET HELPMSG 2273.


C:\Program Files\Support Tools>


That same command run from my DC and i get the message was successfully sent
to COMPUTERNAME.

What gives?