Hi, You can do it in 2 ways: 1) From your Org exchange -> Go to your internet message format ->advanced , clear "allow NDRs" (sorry, don't know the english name) :( 2) Only from your smtp server -> go to your smtp connector -> "contents restrictions" tab and clear "system messages" (sorry, don't know the english name) :( In your case, u may check the second choice because it always takes precedence from the first choice. Hope it helps Yann