2015:02:27-23:01:56 router postfix/qmgr[28512]: 523004C20: from=, size=855, nrcpt=1 (queue active)
2015:02:27-23:01:56 router postfix/smtp[29022]: warning: SASL authentication failure: No worthy mechs found
2015:02:27-23:01:56 router postfix/smtp[29022]: 523004C20: to=, relay=server.mydomain.co.uk[x.y.z.a]:587, delay=1005, delays=1005/0.03/0.3/0, dsn=4.7.0, status=deferred (SASL authentication failed; cannot authenticate to server server.mydomain.co.uk[x.y.z.a]: no mechanism available)