On Yammer as a Network Admin you may monitor certain keywords that you choose. (You need yammer enterprise)

It could be that you as an IT guy want to monitor if users type HELP or PROBLEM or a sentence such as PROBLEM WITH PC

Log in to yammer at Yammer.com

Click the Yammer Cog

yammer cog

Choose Network Admin

network admin

Click Monitor Keywords

monitor keywords

Write the keywords you want to monitor:

keywords

Then when there is a match you will get this email:

email message