Send different email response based on form options?
I experienced the same problem a while ago. I wrote a blog post on it (link below) if you need more information. Basically you can change the email that gets sent based on the input of the form by creating your own webform-mail-[node-id].tpl.php. Within this template you can change the content based on submission data in the $submission variable.

&lt;?php   
  if ($submission-&gt;data[1]['value'][0] == 'General Application'){
    print 'Thank you for submitting your resumé and covering letter'."\n\n";   
  } else {
    print 'Thank you for submitting your resumé and covering letter for the position of '.$submission-&gt;data[1]['value'][0]'."\n\n";   
  } 
 ?&gt;


http://bouncingorange.com/blog/201204/custom-email-templates-webform