Index: mimemail.module
===================================================================
RCS file: /cvs/drupal/contributions/modules/mimemail/mimemail.module,v
retrieving revision 1.44
diff -u -r1.44 mimemail.module
--- mimemail.module	23 Feb 2009 04:28:46 -0000	1.44
+++ mimemail.module	13 Mar 2009 15:34:22 -0000
@@ -102,8 +102,8 @@
     );
   }
 
-  // try to determine recpient's text mail preference
-  if (is_null($plaintext)) {
+  // try to determine recipient's text mail preference
+  if ($plaintext != TRUE) {
     if (is_object($recipient)) {
       if (isset($recipient->mimemail_textonly)) {
         $plaintext = $recipient->mimemail_textonly;