Disable e2ee for use with hamradio-based infrastructure

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Hi,

I’m working on some concepts for AREDN-based communication, which means it is hamradio infrastructure, so encryption is forbidden.

AREDN is a mesh-technology based on a wifi-mesh, which can bridge >60km easily. For max. resilience, it would be perfect to use chatmail-relays, which could be located on different parts of the mesh, so messaging can go on in case of a mesh-fragmentation. Bit since chatmail forces encryption, this is a non-option… :confused:

Alternatively we can use one single standard mailserver and have deltachat as a client, which would still be great, but how can we stop the app from autocrypting the messages? As I understand, encryption is done automatically between deltachat clients, no matter the relay. Is there an option to disable it?

If not, can the server just delete the autocrypt-header, so e2ee cant be established or sth? Some info on how to accomplish this would be great!

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Yes, it’s (still?) possible to use Delta Chat without encryption, with non-Chatmail servers. First set up an account like so FAQ - Delta Chat. Then go to “New Chat” → “New Email”. This option is only available on non-Chatmail servers.

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but is this true for delta2delta, or just for delta2email? Because I need the first szenario, and as I undestand autocrypt, it automatically encrypts normal emails. So Delta only does this with other delta-users?

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Removing of Autocrypt header was implemented in Hermes project and used Delta Chat as a client. I cannot find relevant Postfix configuration in HERMES (High-frequency Emergency and Rural Multimedia Exchange System) · GitHub, but in any case, removing Autocrypt header with Delta Chat is not going to work since v2. Whether the chat is encrypted or not depends on how it was started, so to have unencrypted chats users need to use “New Email” option to send unencrypted message, and if they start encrypted chat the server cannot cause the chat to become unencrypted. With latest versions the first message after QR code scan is encrypted and Autocrypt header in the encrypted part itself, so the server cannot even delete it.

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We could probably set up the server to reject all mail with an encrypted or secure join payload to protect against misclicking, though.

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The easiest thing to practically do currently is to setup latest Delta Chat 1.x and strip Autocrypt header on the server, then you will get chat interface and this is good enough for a setup on a closed network.

Rhizomatica project did remove encryption this way mostly to be able to compress messages I think.

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