We are aware that small number of Microsoft 365 users could still be experiencing delayed delivery or delivery failures for one-time passcodes or other system emails. The underlying issue exists between Microsoft and Highway's independent, third party automated email vendor.
Highway has been asked to direct users who are still experiencing this issue to submit a delisting request per the instructions provided in the error message:
This can be done by sending an email with a copy of the error message, and the blocked IP address, to "delist@microsoft.com". Delisting requests can also be made via the Office 365 Anti-Spam IP Delist Portal at https://sender.office.com/
Unfortunately, the delisting requests must come from directly the intended recipient. Highway is unable to submit delisting requests on behalf of the intended recipient.
Posted Aug 15, 2026 - 14:22 CDT
This incident affected: External API, Broker Web Application, Carrier, and Onboarding.