Hi, there are more email marketing platforms. But Sendinblue servers are located in EU so this is really GDPR compliant. Why does this matter? This article gives a nice overview on that subject
https://matomo.org/blog/2020/07/storing-data-on-us-cloud-servers-dont-comply-with-gdpr/

As I'm operating in the EU the datacenter location should be in Europe. So Sendinblue is my choice!