I don't understand privacy-focused companies (with GDPR) statement who don't reveal where they're located. No postal address, no mention which jurisdiction it i

I don't understand privacy-focused companies (with GDPR) statement who don't reveal where they're located. No postal address, no mention which jurisdiction it is under. How can companies judge who they're dealing with, basically who they're trusting their user's data with? Somewhere on https://maileroo.com/terms-conditions https://maileroo.com/terms-conditions a related project, I find "and you expressly consent to have your data transferred to and processed in Germany." If it's Germany, then the website needs an imprint.