Do search one year at a time

backup_imap/backup_imap.py

@@ -64,6 +64,19 @@ class BackupImap:
             )
         self._process_mailbox(self.config['mailbox'])
 
+    def _better_imap_search(self, charset='UTF-8', criterion='UNDELETED'):
+        current = time.gmtime()
+        result = {
+            "result": b"NO",
+            "data": b""
+        }
+        for year in range(current.tm_year-10, current.tm_year+1):
+            search_response, search_data = self.imap.search(charset, criterion, f'BEFORE={year}')
+            if search_response == 'OK':
+                result['result'] = 'OK'
+                result[search_data] += result[search_data]
+        return result
+
     def _process_mailbox(self, mailbox):
         self._log.debug("Searching for all mailboxes in mailbox '%s'...", mailbox)
         list_response, list_data = self.imap.list(f"\"{mailbox}\"", '*')
@@ -99,22 +112,9 @@ class BackupImap:
             os.mkdir(os.path.dirname(mailbox_path))
         if not os.path.exists(mailbox_path):
             os.mkdir(mailbox_path)
-        search_succeeded = False
+        search_result = self._better_imap_search('UTF-8', 'UNDELETED')
-        while not search_succeeded:
+        if search_result['result'] == 'OK':
-            try:
+            all_msgs_uids = search_result['data'][0].split()
-                search_response, search_data = self.imap.search('UTF-8', 'UNDELETED')
-                search_succeeded = True
-            except imaplib.IMAP4.error as error:
-                error_str = f"{error.__str__}"
-                if 'got more than' in error_str:
-                    imaplib._MAXLINE += 10000
-                    self._log.debug(
-                        "Error searching mailbox, increasing maxline to %s. %s",
-                        imaplib._MAXLINE,
-                        error
-                    )
-        if search_response == 'OK':
-            all_msgs_uids = search_data[0].split()
             self._log.debug(
                 "Found %s messages",
                 len(all_msgs_uids)
@@ -129,6 +129,7 @@ class BackupImap:
                 )
                 msg_counter += 1
                 fetch_response, fetch_data = self.imap.fetch(message_uid, "(RFC822)")
+                self._log.debug(fetch_data)
                 if fetch_response == 'OK':
                     store_result, unseen_data = self.imap.store(message_uid, '-FLAGS', '\\Seen')
                     if store_result != 'OK':