MailerSend is a transactional email service built by the team behind MailerLite. Developers send email through an API or an SMTP relay and use dynamic templates, a drag-and-drop template builder, webhooks, suppression lists and activity logs with analytics. The service also offers inbound routing, which passes customer replies on to your application, and email verification with a validation API. MailerSend is delivered as SaaS and is not open source.
According to its privacy policy, its data storage centres are located in the European Union. The contracting entity named in that policy is MailerSend, Inc., with a registered address in New York. Since 2022 MailerSend has been part of the Polish company Vercom, which acquired MailerLite together with related subsidiaries. For a European organisation this means that data is stored in the EU, while the contracting entity is registered in the United States. Check in the data processing agreement which entity acts as processor and which sub-processors are used.