Using the DSQUERY command, I have scripted NetSendOU.bat to net send a message to all users in a given OU.

The syntax for using NetSendOU.bat is:

NetSendOU OU Message

Where OU is the organizational unit, like "OU=West Coast,DC=JSIINC,DC=COM", and Message is the message text, like "Hello world".

NetSendOU.bat contains:

@echo off
if \{%2\}==\{\} @echo Syntax: NetSendOU OU "Message"&exit /b 1
setlocal
set query=dsquery user %1 -o samid
set message=%2
for /f %%u in ('%query%') do (
 net send "%%u" %message%
)
endlocal
exit /b 0