--- mimemail.install	Thu May 07 14:28:35 2009
+++ mimemail.install	Thu May 07 13:52:30 2009
@@ -15,5 +15,8 @@
   foreach ($variables as $variable) {
     variable_del($variable);
   }
+  if (strpos(variable_get('smtp_library', ''), 'mimemail') !== FALSE) {
+    variable_del('smtp_library');
+  } 
 }