Altering Webform email %value before sending email
In hook_form_alter, add a new submit function before the other submit handlers, like so:

pwe_webform_form_alter(&amp;$form, &amp;$form_state, $form_id) {
  switch($form_id) {
  case 'YOUR_WEBFORM':
       array_unshift($form['#submit'],'pwe_webform_form_submit');
       break;
  } 
}


And then write your submit handler, something like this:

function pwe_webform_form_submit($form, &amp;$form_state){
  $form_state['input']['submitted']['last_name'] = ucfirst($form_state['input']['submitted']['last_name']);
}


You can intercept the submit handler with dpm($form_state['values']) calls, to make sure you're using the right array keys, etc.