You need all the clues that you can find: did you display all the hidden headers e.g., RECEIVED and RESEND headers? Did you do a SCAN of any partial name or mail address? Was the date of the email message recent or old (and thus the person had already unsubscribed e.g., I just starting to receive bounces from mail generated 3 months ago to a then-subscriber). /Pete PS followup to lstown-l only