Disruption to Marshall University E-mail Services 10/23-10/24 October 29, 2021 Description of the Incident: Starting in the evening of Friday October 23 and extending until early afternoon Saturday October 24, there were periodic disruptions in e-mail delivery services for members of the Marshall University community. The disruption was caused by a Microsoft enabled University-wide e-mail security measure – a circuit breaker of sorts – which temporarily blocked all outbound mail delivery from our environment. This restriction was triggered after several University e-mail accounts were used by bad actors to send phishing and scam e-mail messages. MUIT systems administrators worked with Microsoft during this period to identify and reset the outbound delivery restriction. Were any of my outbound message(s) were affected? If you were impacted, an undeliverable message would be generated by your e-mail application or for any IT service using an @marshall.edu e-mail address. The message often begins with ‘Delivery has failed to these recipients or groups:’. No additional delivery attempts for those messages would be made during or once the block was lifted. You will need to resend any messages which were rejected during this time. What steps being taken to prevent future occurrences? MUIT will continue working with business and academic units to ensure all University-e-mail accounts are configured so they can benefit from the service and security features in Microsoft 365. These features include the ability for a restriction to be placed on an individual mailbox and avoid future University-wide disruption of e-mail delivery services. As always, if you need Technical Assistance: Please contact the IT Service Desk via chat at www.marshall.edu/it, phone 304-696-3200, or email email@example.com.