not what you want
My understanding is, the first message send cannot be encrypted because
in the first message person B receives A’s public pgp key. If prefer
end to end encryption is enabled, then B’s reply to A will be encrypted
because he has A’s public pgp key. Next message from A to B is also encrypted,
because A now has B’s public pgp key. Thereby establishing encryption
between A and B.
A and B does not know if an adversary has interfered. Therefore
A and B will have to come up with a way to verify the other person’s
What I want is an option in settings -> autocrypt called force encryption such that
if selected every contact with whom encrypted messaging has been
established will only receive encrypted messages. Else the message
will not get send. If sending a message to a contact fails and
delta chat tells it failed because the message could not get encrypted,
then I would write the contact an email in order to find out why encryption
failed. It should be workable, because I expect that encryption in
In result, if encrypted messaging in delta chat has been established, then I do
not want to be able to send non encrypted messages to a contact. For
non end to end encrypted messaging I can use an email.
showing whether a message will be encrypted before sending
That would also do. But if encryption to a contact has been established and
at one point delta chat says, the next message will not be encrypted, then I would
want delta chat to display the notification in a big window you would
have to close before continuing.