title: Sitecore ECM - Do not send to duplicate email addresses
body: <p>Does anyone know if there is a setting in Sitecore ECM which will disable sending to duplicate email addresses (Sitecore 6.5 rev 706 ECM 1.3.2 rev 120424). I haven't found any mention in the dev docs - but it seems like it is a common requirement. Or am I going to need to override the send pipeline and implement this as custom functionality? </p>
  
  <p>Cheers </p>