Reuse the same hash in the loop, modifying the unique keys.

lib/WebGUI/Account/Inbox.pm

@@ -1151,14 +1151,16 @@ sub www_sendMessageSave {
     #Let sendMessage deal with displaying errors
     return $self->www_sendMessage($errorMsg) if $hasError;
 
-    foreach my $uid (@toUsers) {
+    my $messageProperties = {
-        $inbox->addMessage({
         message => $message,
         subject => $subject,
-            userId  => $uid,
         status  => 'unread',
         sentBy  => $fromUser->userId
-        });
+    };
+
+    foreach my $uid (@toUsers) {
+        $messageProperties->{userId} = $uid;
+        $inbox->addMessage($messageProperties);
     }
 
     $self->appendCommonVars($var,$inbox);