Removed X-MSMail-Priority

app/src/main/java/eu/faircode/email/MessageHelper.java

@@ -284,13 +284,20 @@ public class MessageHelper {
             imessage.addHeader("Importance", "Low");
             imessage.addHeader("Priority", "Non-Urgent");
             imessage.addHeader("X-Priority", "5"); // Lowest
-            imessage.addHeader("X-MSMail-Priority", "Low");
+            //imessage.addHeader("X-MSMail-Priority", "Low");
+            // SpamAssassin Rule: MISSING_MIMEOLE
+            // Standard description: Message has X-MSMail-Priority, but no X-MimeOLE
+            // Explanation: The message is pretending to be generated by a Microsoft email program
+            // which uses the extension header X-MSMail-Priority,
+            // but is missing the extension header X-MimeOLE which is characteristic of Microsoft email.
+            // This suggests that the sender is using badly-written mailout software,
+            // rather than a genuine Microsoft email program.
         } else if (EntityMessage.PRIORITIY_HIGH.equals(message.priority)) {
             // High
             imessage.addHeader("Importance", "High");
             imessage.addHeader("Priority", "Urgent");
             imessage.addHeader("X-Priority", "1"); // Highest
-            imessage.addHeader("X-MSMail-Priority", "High");
+            //imessage.addHeader("X-MSMail-Priority", "High");
         }
 
         // Sensitivity