Mac Mail recovery from my own stupidity

recently, we have changed email providers to become more professional.
The old address is going away and the new address has been
implemented. In my haste to make the email on my Mac cleaner, I
deleted the old account after having all new mail forwarded to the new
account from the old account. Long story short, I willingly deleted the
email profile and five years worth of email out of Apple Mail 2.1 and now
I need it back. I was hoping to hear that Apple Mail is similar to Outlook
in that maybe I could just find the pst-type file and open it back up. But
to no success. And the trash bin is clean. Any suggestions????