What might be causing this batch of errors in zimbra.log...and all incoming messages to be put into deferred queue?
Apr 17 10:46:26 smtp postfix/smtp[3632]: 78242FC8F0: to=<shannons@creative-lighting.com>, relay=127.0.0.1[127.0.0.1]:10024, delay=0.65, delays=0.06/0/0/0.58, dsn=2.0.0, status=sent (250 2.0.0 Ok: queued as 16E8EFC907)
Apr 17 10:46:26 smtp postfix/smtp[3632]: 78242FC8F0: to=<tammy@creative-lighting.com>, relay=127.0.0.1[127.0.0.1]:10024, delay=0.65, delays=0.06/0/0/0.58, dsn=2.0.0, status=sent (250 2.0.0 Ok: queued as 16E8EFC907)
Apr 17 10:46:26 smtp postfix/qmgr[6252]: 78242FC8F0: removed
Apr 17 10:46:26 smtp postfix/qmgr[6252]: warning: connect to transport retry: No such file or directory
Apr 17 10:46:26 smtp postfix/qmgr[6252]: 16E8EFC907: to=<brendad@creative-lighting.com>, relay=none, delay=0.08, delays=0.02/0.06/0/0, dsn=4.3.0, status=deferred (mail transport unavailable)