Email delivery has returned to normal. Microsoft have reported that the issue was a result of a SPAM restriction policy introduced for Australian Tenants. No further delays are expected.
Posted Nov 19, 2019 - 23:30 AEDT
Monitoring
We have reports of email delivery being delayed for some Office 365 tenants.
Microsoft have released an Incident Statement related to this issue (EX196121)
Quote: --- Title: Problems receiving mail
User Impact: Users may not receive emails sent from external users.
More info: Messages sent internally between users are not impacted.
Current status: We suspect there is a networking issue that is causing impact. We're continuing our investigation of network logs.
Scope of impact: This issue could potentially impact any users receiving emails from external users. ---
No remediation works are required at this stage, however our technicians will continue to monitor this incident to ensure that services self recover.