handle maxline

backup_imap/backup_imap.py

@@ -101,7 +101,18 @@ class BackupImap:
             os.mkdir(os.path.dirname(mailbox_path))
         if not os.path.exists(mailbox_path):
             os.mkdir(mailbox_path)
-        search_response, search_data = self.imap.search('UTF-8', 'UNDELETED')
+        search_succeeded = False
+        while not search_succeeded:
+            try:
+                search_response, search_data = self.imap.search('UTF-8', 'UNDELETED')
+                search_succeeded = True
+            except Exception as error:
+                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(