Force.com Email Services or “email to Apex” lets you define email addresses, which can process Apex code. Send emails to Salesforce and process them with Apex code to create and update data from inbound emails.

Following sample code @ Apex Wiki shows you how an email can be used to create new tasks for a contact record with a matching email address i.e., Send an email to Salesforce with a follow-up note, will setup a task with a reminder 1 day for now.

Retrieved from “http://wiki.apexdevnet.com/index.php/Force.com_Email_Services