Thanks all. --- I've expanded my reporting.......I am getting various responses like:
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Based on the information you have provided, this may have originated from an account hosted on Microsoft Azure.
We forwarded your complaint to the CERT team for review and action.
Should you encounter additional reports from the same IP, send them directly to Cert@Microsoft.com.
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or
Based on the information you provided, it appears to have originated from an Office 365 or Exchange Online tenant account.
To report junk mail from Office 365 tenants, send an email to junk@office365.microsoft.com and include the junk mail as an attachment.
Hopefully they can make it stop.