Migrated from 13" MacBookPro to 15" MacBook Retina via the Genius bar. Old mail did not migrate over but is on TimeCapsule backup. How can I retrieve the old emails?

I upgraded from a 13" MacBook Pro to the 15" MacBook Pro Retina. I took both laptops to the Genius bar for them to do the migration. Because of an issue with using the Firewire port in my old laptop for the transfer, I had to leave the laptops overnight. The good news is that they were finally able to migrate my data from the old laptop to the new one. The bad news is that they did not transfer my iMail, so I lost tons of saved emails that are very important. This is very frustrating because I had to pay for the migration and had no idea until I got home that my iMail didn't transfer. My old laptop has been now reconfigured for my son, so my old data on that laptop was wiped after it was transferred to my new laptop.

Prior to the migration, I had been backing up my old laptop to TimeCapsule; I did a back up the morning of the migration. I am wondering if there is a way to retrieve the old emails from TimeCapsule so that I do not lose them. Is this even possible and if so, how do I go about doing it?

Teresa