Index: mimemail.module
===================================================================
--- mimemail.module	(revision 2127)
+++ mimemail.module	(working copy)
@@ -207,6 +207,14 @@
 
   $engine = variable_get('mimemail_engine', 'mimemail') .'_mailengine';
   
+  // Backward compatabile mail_alter call to work with legacy modules doing mail_alter's
+  //  - doesn't support passing all the variables used here (e.g. attachements)
+  //  - should also provide a hook_mimemail_alter for full mimemail support
+  foreach (module_implements('mail_alter') AS $module) {
+    $function = $module .'_mail_alter';
+    $function($mailkey, $recipient, $subject, $body, $sender, $headers);
+  }
+  
   if (!function_exists($engine)) {
     return false;
   }