And there goes a successful mail test.
Mar 7 11:25:24 relay01 postfix/smtpd[2206]: connect from owncloud.domain.local[10.201.1.17]
Mar 7 11:25:24 relay01 postfix/smtpd[2206]: CB2E6C0C82CB: client=owncloud.domain.local[10.201.1.17]
Mar 7 11:25:24 relay01 postfix/cleanup[2208]: CB2E6C0C82CB: message-id=<adbc9eb08cdcc4b8e90d2cddad5e079e@oc.domain.com>
Mar 7 11:25:24 relay01 postfix/qmgr[1665]: CB2E6C0C82CB: from=<admin@domain.com>, size=591, nrcpt=1 (queue active)
Mar 7 11:25:24 relay01 postfix/smtpd[2206]: disconnect from owncloud.domain.local[10.201.1.17]
Mar 7 11:25:26 relay01 postfix/smtp[2209]: CB2E6C0C82CB: to=<admin@domain.com>, relay=domain-com.mail.protection.outlook.com[216.32.181.170]:25, delay=2.1, delays=0.05/0/0.62/1.4, dsn=2.6.0, status=sent (250 2.6.0 <adbc9eb08cdcc4b8e90d2cddad5e079e@oc.domain.com> [InternalId=42704859829911, Hostname=SN1PR0201MB1854.namprd02.prod.outlook.com] 7564 bytes in 0.244, 30.254 KB/sec Queued mail for delivery)
Mar 7 11:25:26 relay01 postfix/qmgr[1665]: CB2E6C0C82CB: removed