Communication Services: Issues with Azure Communication Services Email in Canada — Clarification on Data Residency and Processing

Problem descriptionI am evaluating Azure Communication Services (ACS) Email for a Canadian healthcare application and require clarification regarding Canadian data residency and transient processing before determining whether the service is appropriate for production use.When an ACS Email resource is configured with Data Location = Canada, can Microsoft confirm:Are email bodies and attachments processed exclusively within Canada throughout the complete email-delivery lifecycle?Can transient operations—including queuing, malware/security scanning, retry handling and failed-delivery processing—occur outside Canada?If processing can occur outside Canada, which countries, Azure geographies or geographic regions may be involved?If an attachment is encrypted by the application before submission to ACS Email, and Microsoft is not provided the decryption password/key, would Microsoft systems involved in processing have access only to the encrypted attachment rather than its underlying contents?Is there any ACS Email configuration, service tier or contractual commitment that guarantees email content and attachments remain exclusively within Canada for both storage and transient processing?EnvironmentAzure Communication Services Email

Data Location: Canada Intended use: Canadian healthcare applicationWhat I've already triedI have reviewed the public Azure Communication Services privacy/data-residency documentation and have also contacted Microsoft Support.My understanding from the information received so far is that data stored at rest can be associated with the selected geography, but the available documentation does not provide an ACS Email-specific guarantee that all transient processing remains within Canada.I have also been unable to find documentation identifying the geographic locations in which transient ACS Email processing may occur.Current statusI need an authoritative clarification regarding the above before completing a healthcare privacy/security and vendor assessment.If ACS Email cannot guarantee Canada-only transient processing, confirmation of that limitation would also answer the question.Links to any applicable Microsoft documentation, contractual commitments, Data Protection Addendum provisions, or ACS Email-specific data-residency documentation would be greatly appreciated.