Index: mimemail.module
===================================================================
RCS file: /cvs/drupal/contributions/modules/mimemail/mimemail.module,v
retrieving revision 1.31.2.3
diff -u -r1.31.2.3 mimemail.module
--- mimemail.module	14 Apr 2009 23:08:59 -0000	1.31.2.3
+++ mimemail.module	31 Mar 2010 11:03:50 -0000
@@ -6,6 +6,15 @@
  */
 
 /**
+ * Implementation of hook_disable().
+ */
+function mimemail_disable() {
+  if (strpos(variable_get('smtp_library', ''), 'mimemail') !== FALSE) {
+    variable_del('smtp_library');
+  }
+}
+
+/**
  * Implementation of hook_menu()
  */
 function mimemail_menu() {