To comply with GDPR legislation and to keep the information about your customers, who are EU residents, inside the EU for processing, you must update the Sitecore SMTP, EDS, and Sparkpost configurations. You must perform these updates on all content management (CM) roles and dedicated email dispatch server (DDS) roles, and in agreement with Sitecore.
Please note that the data center region of the Email Cloud and Sparkpost servers is defined in the service order. For more details, contact your Sitecore sales representative.
Once a data center is defined and settled, it cannot switch from one region to another.