Where is GMX net located?

Could you please clarify the location of GMX net for me? I'm interested in understanding more about the physical or operational headquarters of this platform, as well as any regional offices or servers they may have. It's important to me to have a clear picture of where GMX net operates from, and whether they have a strong global presence. Could you provide me with the country, city, and any other relevant details regarding their location? Thank you in advance for your assistance.