Yesterday someone (from another domain and email server - Zimbra) emailed a list then tried to recall the email. My users have mail boxes on my exchange 2007 but also have emails forwarded from the Zimbra server to my exchange. The recall set of a firestorm of Message Recall Failure emails. Worse yet my exchange was sending the failures for each email to the entire list. How can I diasble the Message Recall Failure notice in Exchange 2007 to prevent this from happening again?