Updated text

app/src/main/res/values/strings.xml

@@ -276,7 +276,7 @@
     <string name="title_advanced_threading">Conversation threading</string>
     <string name="title_advanced_indentation">Left/right indent received/sent messages in conversations</string>
     <string name="title_advanced_highlight_unread">Highlight unread messages</string>
-    <string name="title_advanced_distinguish_contacts">Distinguish messages from known and unknown contacts</string>
+    <string name="title_advanced_distinguish_contacts">Underline the sender when the sender is known as local \'to\' contact</string>
     <string name="title_advanced_color_stripe">Show color stripe</string>
     <string name="title_advanced_avatars">Show contact photos</string>
     <string name="title_advanced_generated_icons">Show generated icons</string>