bitkasten AG is a German software-as-a-service (SaaS) and clean-tech provider for the complete digitisation of mail communication and information exchange. The solution is the bitkasten, a digitalisation and communication platform - ecological, sustainable and smart. With the bitkasten, companies and municipalities bridge the ""last mile"" to the customer/citizen by digitising input and output processes. This is done without a costly IT project within a short time by using existing print data and postal addresses. This sustainable mail communication, digital and without printing & transport, leads to a cutting in half of printing, postage and process costs with ROI within a few weeks. With bitkasten, companies and government administrations communicate securely with their recipients - without email. Documents are delivered to the digital, smart letterbox in a legally compliant manner. The bitkasten stands for fast communication like email, but without an email address, but secure and DSGVO-compliant. The identification and digital delivery of the communication will be based on the known postal address via the electronic ID card or identifier. For the recipient, communication in the bitkasten works without media disruption via app or web. The bitkasten receives mail digitally from all participating senders, provides the option of a digital signature and transmits data to ERP, CRM and HR systems or directly to specialised procedures in the municipal environment. By mapping processes, input options or forms in the closed system of the bitkasten, the recipient is securely connected to the company or the administration.