Below is a list of common error codes and the reasons they occur.
Common POP3 Error Codes
- +OK – The server has successfully processed the client's request. This is a positive response indicating that the previous command was successful.
- -ERR – The server encountered an error while processing the client's request. This is a negative response indicating that the previous command failed.
Specific POP3 Error Scenarios
- -ERR User not found – The specified user does not exist. Check the username and try again.
- -ERR Invalid password – The password provided is incorrect (try to update your password).
- -ERR Mailbox not found – The specified mailbox does not exist. Verify the mailbox name.
- -ERR Cannot connect to server – There was an issue connecting to the server. The server might be down or experiencing high load.
- -ERR Connection timed out – The connection to the server timed out. Try reconnecting.
- -ERR Too many connections – The server is experiencing too many simultaneous connections. Try again later.
- -ERR Server temporarily unavailable – The server is temporarily unavailable due to maintenance or high load. Try again later.
- -ERR Disk quota exceeded – The user's disk quota has been exceeded. Free up space by deleting unnecessary emails or attachments.
- -ERR Mailbox locked – The mailbox is currently locked. This can happen if another session is accessing the mailbox. Try again later.
- -ERR Permission denied – The user does not have the necessary permissions to perform the requested operation.
- -ERR Message not found – The specified message does not exist. Verify the message ID.
- -ERR Message already deleted – The specified message has already been deleted.
- -ERR Unknown command – The server did not recognize the command. Verify the command syntax.