in delta chat you can export your public key as vcard, you then need to import that key from that vcard in the other email clients that support encryption, if the other person share their key via another channel, you could even convert their key (.asc file) to a vcard and import it in your delta chat so you can immediately send encrypted to that person and they can send encrypted to you with the key you shared with them, I think this will work even without autocrypt at all, so the steps are:
- Share your public key with your peer via another communication medium
- go to Saved Messages
- click attackment button
- select the contact button to attack contact
- scroll to the bottom of the contact list that appear and select the last item that is your own contact
- send the attached contact in the Saved Messages chat
- select the message you just sent with your contact info, select “export attachment” this will export a vcard file
- share the vcard file with your friend
- if your friend doesn’t have a client that can import encryption keys from vcard (ex. protonmail can) then you will need to first edit the vcard in a text editor and extract the key and convert it to an .asc file and share that .asc file with your friend
- In another communication channel, ask your friend to send you their public key (.asc file or or .vcard in the case of ProtonMail)
- if they sent you a .asc file you will need to use an in-chat tool we have called “.asc to VCard” see it here: webxdc apps with this tool you can convert .asc to vcard that you can import in your delta chat
- send the received .vcard file in your “Saved Messages” chat and click it, this will import the key of your contact
- now you can start sending encrypted messages to your contact!