Nintex Workflow for Office 365 - Workflow Failing with Assign a Task and Send An Email Action

We are aware of an issue where workflow are falling Assign a Task and Send An Email Action.

Sample error:
For O365 - "Microsoft.SharePoint.SPException","message":{"lang":"en-US","value":"The e-mail message cannot be sent. Make sure the e-mail has a valid recipient."}}}"."

We have identified that the issue is occurring with the Microsoft Infrastructure of Office 365. Small subset of customers in the NEU region maybe impacted.

We have raised a Sev A ticket with Microsoft support and will update this ticket as more information is available.

We recommend customers encountering this issue raise a ticket with Microsoft directly via their Office 365 admin portal.
You may reference to MS ticket of #‎2512100030003457.

The Nintex engineering team has reached out to Microsoft Support for further investigation. Microsoft Support to escalate to Microsoft PG team for further investigation.

We recommend customers encountering this issue raise a ticket with Microsoft directly via their Office 365 admin portal. You may quote the reference of #2512100030003457.