You get free access to an usable end-to-end encryption mail client on iOS (Letterbox) and in return we ask you to support us to understand and to improve secure communication. We do not provide any incentive or compentsation to participate in our short study but you can be part of improving secure communication.

What do you have to do?

What do we offer?

You can find a more detail overview here. When using Letterbox we are collecting meta data. Please read the privacy policy for more information.

Letterbox is a research project and still under development. At the moment, we can only offer a beta version and this version may contain bugs or other errors.

Please use Letterbox only at your own risk!

Try Letterbox