Fixed IMAP SEARCH BEFORE command

tests/resources/scripts/imap_import.py

@@ -3,6 +3,8 @@ import socket
 import time
 import threading
 from email.message import Message
+from email.utils import formatdate
+from datetime import datetime, timedelta
 
 def append_message(thread_id, start, end):
     conn = imaplib.IMAP4('localhost')
@@ -10,15 +12,20 @@ def append_message(thread_id, start, end):
     conn.socket().setsockopt(socket.IPPROTO_TCP, socket.TCP_NODELAY, 1)
     start_time = time.time()
 
+    base_date = datetime(2000, 1, 1)
+
     for n in range(start, end):
+        current_date = base_date + timedelta(hours=n)
+
         msg = Message()
         msg['From'] = 'somebody@some.where'
         msg['To'] = 'john@example.org'
         msg['Message-Id'] = f'unique.message.id.{n}@nowhere'
+        msg['Date'] = formatdate(time.mktime(current_date.timetuple()), localtime=False, usegmt=True)
         msg['Subject'] = f"This is message #{n}"
         msg.set_payload('...nothing...')
 
-        response_code, response_details = conn.append('INBOX', '', None, str(msg).encode('utf-8'))
+        response_code, response_details = conn.append('INBOX', '', imaplib.Time2Internaldate(time.mktime(current_date.timetuple())), str(msg).encode('utf-8'))
         if response_code != 'OK':
             print(f'Thread {thread_id}: Error while appending message #{n}: {response_code} {response_details}')
             break