Fix OVER value encoding

lib/nntp/tiny/session.py

@@ -4,6 +4,8 @@ import socket
 import datetime
 import fnmatch
 import traceback
+import email.header
+import email.utils
 
 from typing import Optional
 
@@ -680,9 +682,9 @@ class Session():
     def _message_overview(self, message: Message) -> dict:
         return map(lambda s: s.replace('\t', ' '), [
             str(message.id),
-            message.subject,
-            message.sender,
-            message.created_on.isoformat(),
+            email.header.Header(message.subject).encode(),
+            email.header.Header(message.sender).encode(),
+            email.utils.format_datetime(message.created_on),
             message.message_id,
             message.parent_id or '',
             str(len(message.content)),