When you say "backup all my data", what exactly does that mean? That is, did you just backup "everything" except the OS?
One of the folders created with the OS (along with the setup procedure ones goes through) is called Users, located at the "root" level (that is, after you boot up your Mac and click on the hard disk/partition that contains the OS and your applications). Within the Users folder, there is another one that (typically) is named with your name (or whatever you used when you ran through the setup). Within that folder, there is one called Documents, and within that one is one called Microsoft User Data (assuming you use Office), and within that is one called Office 2008 Identities (in your case; mine says Office 2011 Identities). Within that, there is a folder that is called Main Identity. That is the one that contains the database with all your EMails (included deleted ones). If prior to your crash you have a backup of your system, then you could get that Main Identity folder from the last "good" backup you made.