feat: add option to force encryption

src/e2ee.rs

@@ -109,6 +109,7 @@ pub async fn ensure_secret_key_exists(context: &Context) -> Result<()> {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::chat;
     use crate::chat::send_text_msg;
     use crate::config::Config;
     use crate::message::Message;
@@ -155,6 +156,19 @@ Sent with my Delta Chat Messenger: https://delta.chat";
         );
     }
 
+    #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+    async fn test_cannot_send_unencrypted_by_default() -> Result<()> {
+        let mut tcm = TestContextManager::new();
+        let alice = &tcm.alice().await;
+        let bob = &tcm.bob().await;
+        let chat = alice.create_email_chat(bob).await;
+
+        let mut msg = Message::new_text("Hello!".to_string());
+        assert!(chat::send_msg(alice, chat.id, &mut msg).await.is_err());
+
+        Ok(())
+    }
+
     #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
     async fn test_chatmail_can_send_unencrypted() -> Result<()> {
         let mut tcm = TestContextManager::new();