About the project

Project Name: Delta Chat E-mail Provider Portability Directory (EPPD)

The Delta chat E-Mail Provider Portability directory project will support informed user decisions about choosing or changing an e-mail provider for use with Delta Chat, a unique e-mail based messaging approach.

Team: Holger Krekel, Henriette Signer and Bjoern Petersen

The EPPD project will research relevant criteria for comparing e-mail providers for use with Delta Chat apps. We will develop automated tests to continuously produce per-provider data. The criteria will include rate-limits for sending and receiving messages (per hour, per day, per month), limits on message size, interoperability ratings with other providers, speed of message delivery and other criteria.

Website: delta.chat

Achievements from the first phase of the DAPSI programme

A major part of our phase 1 effort focused on interviewing expert users and publishing a set of e-mail provider comparison criteria to compare a total of twenty international popular e-mail providers.

Moreover, we realized two releases for Android and iOS versions to improve usability in Delta Chat apps for onboarding, as well as for provider connectivity and constraints: https://delta.chat/en/2021-08-24-updates

Last but not least, we worked on developing a business model for Delta Chat beyond DAPSI funding by discussing a variety of possibilities with our DAPSI business coach, Etienne Krieger, and meeting with potential business partners to discuss collaborations.



Our DAPSI participation and funding helped us to assess our needs and identifying potential business opportunities. It allowed us to push the development of our email-based messenger, Delta Chat, and help our users to understand the importance of data portability and choosing a suitable provider.

Henriette Signer


    Holger Krekel

    Holger is long-term involved with Delta Chat as research & development co-ordinator.

      Henriette Signer

      Henriette joined Delta Chat efforts as technical coordinator, bringing extensive experience in international communications.

        Bjoern Petersen

        Bjoern leads mobile developments and the integration of provider-specific behaviour into all Delta Chat apps.


        merlinux GmbH
        merlinux GmbH
        merlinux is fiscal sponsor for Delta Chat developments and carries out R&D projects.