diff --git a/src/dc_receive_imf.rs b/src/dc_receive_imf.rs
index 6e4007bfc..d2f52330d 100644
--- a/src/dc_receive_imf.rs
+++ b/src/dc_receive_imf.rs
@@ -4845,4 +4845,31 @@ Message with references."#;
 
         Ok(())
     }
+
+    /// Test a message with RFC 1847 encapsulation as created by Thunderbird.
+    #[async_std::test]
+    async fn test_rfc1847_encapsulation() -> Result<()> {
+        let alice = TestContext::new_alice().await;
+        let bob = TestContext::new_bob().await;
+        alice.configure_addr("alice@example.org").await;
+
+        // Alice sends an Autocrypt message to Bob so Bob gets Alice's key.
+        let chat_alice = alice.create_chat(&bob).await;
+        let first_msg = alice
+            .send_text(chat_alice.id, "Sending Alice key to Bob.")
+            .await;
+        bob.recv_msg(&first_msg).await;
+        message::delete_msgs(&bob, &[bob.get_last_msg().await.id]).await?;
+
+        bob.set_config(Config::ShowEmails, Some("2")).await?;
+
+        // Alice sends a message to Bob using Thunderbird.
+        let raw = include_bytes!("../test-data/message/rfc1847_encapsulation.eml");
+        dc_receive_imf(&bob, raw, "INBOX", 2, false).await?;
+
+        let msg = bob.get_last_msg().await;
+        assert!(msg.get_showpadlock());
+
+        Ok(())
+    }
 }
diff --git a/test-data/message/rfc1847_encapsulation.eml b/test-data/message/rfc1847_encapsulation.eml
new file mode 100644
index 000000000..25cb52d5d
--- /dev/null
+++ b/test-data/message/rfc1847_encapsulation.eml
@@ -0,0 +1,60 @@
+Message-ID: <4718cf7f-67f4-291b-ccb9-a167842729ed@example.org>
+Date: Sun, 5 Dec 2021 00:00:00 +0000
+MIME-Version: 1.0
+User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101
+ Thunderbird/91.3.2
+Content-Language: en-US
+To: Bob <bob@example.net>
+From: Alice <alice@example.org>
+Subject: ...
+Content-Type: multipart/encrypted;
+ protocol="application/pgp-encrypted";
+ boundary="------------68Kl9HSVGFVUMdZIowLUKskt"
+
+This is an OpenPGP/MIME encrypted message (RFC 4880 and 3156)
+--------------68Kl9HSVGFVUMdZIowLUKskt
+Content-Type: application/pgp-encrypted
+Content-Description: PGP/MIME version identification
+
+Version: 1
+
+--------------68Kl9HSVGFVUMdZIowLUKskt
+Content-Type: application/octet-stream; name="encrypted.asc"
+Content-Description: OpenPGP encrypted message
+Content-Disposition: inline; filename="encrypted.asc"
+
+-----BEGIN PGP MESSAGE-----
+
+wV4D5tq63hTeebASAQdAt2c3rVUh+l0Ps7/Je83NaA7M6HsobtfMueqLUBaeancw0rRAo7PbLDLL
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+ofVNpLp9SUsrtXbFp89Dxiuflj10VvcLGU2AjSsUtjEpPl0nobeJmA3RzFxJZ61RG+E=
+=dcQr
+-----END PGP MESSAGE-----
+
+--------------68Kl9HSVGFVUMdZIowLUKskt--