Your administrator should have setup an individual email signature or a company standard signature for you to select and apply to your account. This signature will be used when you send emails from Tracker.
Click on your name in the top right corner of your screen.
Select My Settings.
Scroll down to My Email Signatures & Aliases and select the email signature you want to use.
Save settings at the top right of your page. Now, when you send emails out of Tracker it will contain this email signature.