Postmark is an email delivery service provider used within Healthtech 1 to send notification emails to practices.
Access control: We restrict access to personal data only to our employees, contractors, and agents who need to know this information in order to operate, develop, or improve our service. Only a select few have access to the servers where data is stored. We go to great lengths to ensure the right balance between support and secure infrastructure. Employees can only access accounts if they have explicit permission from an account owner or the account is in review for compliance with the Postmark Terms of Use. The only teams that have access are customer support and engineering.
https://postmarkapp.com/support/article/917-is-postmark-secure-and-redundant