root@mail log]# grep C00681EB9DFD maillog
Sep 14 14:17:52 mail postfix/pickup[24843]: C00681EB9DFD: uid=0 from=<bounces@out.byside.com>
Sep 14 14:17:52 mail postfix/cleanup[24675]: C00681EB9DFD: message-id=<5978d074c832d24023acf896bede6247@localhost.localdomain>
Sep 14 14:17:53 mail postfix/qmgr[11714]: C00681EB9DFD: from=<bounces@out.byside.com>, size=287532, nrcpt=1 (queue active)
Sep 14 14:17:57 mail postfix/qmgr[11714]: C00681EB9DFD: to=<auto-jocar@sapo.pt>, relay=none, delay=5.3, delays=0.9/4.4/0/0, dsn=4.3.0, status=deferred (unknown mail transport error)
Sep 14 15:17:03 mail postfix/qmgr[11714]: C00681EB9DFD: from=<bounces@out.byside.com>, size=287532, nrcpt=1 (queue active)
Sep 14 15:22:21 mail postfix/qmgr[11714]: C00681EB9DFD: to=<auto-jocar@sapo.pt>, relay=none, delay=3869, delays=3551/318/0/0, dsn=4.3.0, status=deferred (unknown mail transport error)
Sep 14 18:43:08 mail postfix/qmgr[6707]: C00681EB9DFD: from=<bounces@out.byside.com>, size=287532, nrcpt=1 (queue active)
Sep 14 18:43:08 mail postfix/qmgr[6707]: C00681EB9DFD: to=<auto-jocar@sapo.pt>, relay=none, delay=15916, delays=15916/0.26/0/0, dsn=4.3.0, status=deferred (unknown mail transport error)
Sep 14 20:32:34 mail postfix/qmgr[27115]: C00681EB9DFD: from=<bounces@out.byside.com>, size=287532, nrcpt=1 (queue active)
Sep 14 20:32:34 mail postfix/qmgr[27115]: C00681EB9DFD: to=<auto-jocar@sapo.pt>, relay=none, delay=22482, delays=22482/0.05/0/0, dsn=4.3.0, status=deferred (unknown mail transport error)