How to fetch and process mail in order to execute commands?

I administer a home server, and sometimes when I'm out, I need to execute some simple commands on the server. 3G + SSH is not an option because it's too expensive from my phone (here in Argentina). It is easier to send an SMS to my mail account. I want to fetch the mails I send to my server, and process the text surrounded by ** as bash commands. What approach would you recommend?