mail continuously resent despite output queue being empty

view story

http://stackoverflow.com – On linux, ubuntu I have an old message stuck somewhere. The recipient's address is invalid and the system keeps trying to re-send despite mail output queue being supposedly empty. Any ideas where I should look for the stuck message? ~$ mailq mailq: Mail queue is empty ~$ sendmail -bp sendmail: Mail queue is empty My /var/log/mail reads: Jan 3 17:00:02 my-linux-box sSMTP[15504]: Creating SSL connection to host Jan 3 17:00:03 my-linux-box sSMTP[15504]: SSL connection using RSA_ARCFOUR_SHA1 Jan 3 17:00:07 my-linux-box sSMTP[15504]: Sent mail for [email protected] (221 2.0.0 BLU0-SMTP35.bl (HowTos)