You can write apex inbound email service class to get the email information and do your logic accordingly. Check the below sample code
 

global class tasks implements Messaging.InboundEmailHandler {
global Messaging.InboundEmailResult handleInboundEmail(Messaging.inboundEmail email, 
                                                  Messaging.InboundEnvelope env){
Messaging.InboundEmailResult result = new Messaging.InboundEmailResult();
String myPlainText = '';
try
{
      myPlainText = email.plainTextBody.substring(0, email.plainTextBody.indexOf('<stop>'));
}
catch (System.StringException e)
{
     myPlainText = email.plainTextBody;
     System.debug('No <stop> in email: ' + e);
}
    // Try to lookup any contacts based on the email from address
    // If there is more than 1 contact with the same email address
    // an exception will be thrown and the catch statement will be called
try {
       Contact vCon = [Select Id, Name, Email
       From Contact  
       Where Email =email.fromAddress
       Limit 1];
      
      Contact con = new Contact(); 
      vCon.FirstName = email.fromname.substring(0,email.fromname.indexOf(' ')); 
      vCon.LastName = email.fromname.substring(email.fromname.indexOf(' ')); 
      vCon.Email = envelope.fromAddress; 
      upsert vCon;
}
   catch (System.QueryException e) {
      System.debug('Query Issue: ' + e);
 }
  result.success = true;
  return result;
}

}

Check this link for more details about inbound email service - https://developer.salesforce.com/page/Force.com_Email_Services
Blog post - http://blog.jeffdouglas.com/2010/03/12/writing-an-inbound-email-service-for-salesforce-com/