The good news is that you don’t need to receive a presale email to access the Frontier Member presale.  

You can view the presale information on the Frontier Touring website from the time a tour is announced until the end of the tour’s presale period. Head to the the relevant artist's tour page on the Frontier Touring website and select either "Presale soon" or “Presale on now” for your chosen show date. This will then prompt you to Sign in to view your presale code.