In addition to Matt's response, you can also review this information within the headers of the message, this is useful for grabbing the Reply-To section which is often exploited by spammers. Sometimes they will use a spoofed from address and the reply-to can sometimes be used to identify the domain of origin. These can be accessed when viewing the message within the web interface by selecting View -> Headers from the action bar.
I hope this helps.
Von See
Technical Support Supervisor
SmarterTools Inc.
(877) 357-6278
www.smartertools.com