Parse <blockquote> tags for better quote detection (#2313)

src/mimeparser.rs

@@ -2744,6 +2744,19 @@ On 2020-10-25, Bob wrote:
         assert_eq!(mimeparser.parts[0].param.get(Param::Quote).unwrap(), "Now?");
     }
 
+    #[async_std::test]
+    async fn test_allinkl_blockquote() {
+        // all-inkl.com puts quotes into `<blockquote> </blockquote>`.
+        let t = TestContext::new().await;
+        let raw = include_bytes!("../test-data/message/allinkl-quote.eml");
+        let mimeparser = MimeMessage::from_bytes(&t, raw).await.unwrap();
+        assert!(mimeparser.parts[0].msg.starts_with("It's 1.0."));
+        assert_eq!(
+            mimeparser.parts[0].param.get(Param::Quote).unwrap(),
+            "What's the version?"
+        );
+    }
+
     #[async_std::test]
     async fn test_add_subj_to_multimedia_msg() {
         let t = TestContext::new_alice().await;