imapclient.exceptions.ProtocolError: Server replied with a response that violates the IMAP protocol

[foxsam21]

Sometimes I get this error after new email is received.
imapclient.exceptions.ProtocolError: Server replied with a response that violates the IMAP protocol
I ran my code with debugging and the log is available here: https://pastebin.com/4Pc46YRD

I am connectting to gmail imap server and I am not sure how to fully reproduce this error. But it always happens eventually and only after mail is received.

[mjs]

The debug output is super useful. Thanks for collecting it.

It looks like Gmail is sometimes not returning a valid untagged response (note how 14 FLAGS (\Seen)) doesn't begin with *). I'll have to double check the specs to make sure IMAPClient is doing everything right but we might have to make IMAPClient a bit more relaxed about what it accepts or something.

[christianbur]

Here's a few more examples.
the problem concerns only with dovecot (mailcow) but not with gmx.de or gmail.com

2018-09-17 17:28:26,560 - Thread-mail_example.de_mx1 - DEBUG: IMAP IDLE response: []
2018-09-17 17:28:26,572 - Thread-mail_example.de_mx1 - DEBUG: < b'here'
2018-09-17 17:28:26,572 - Thread-mail_example.de_mx1 - ERROR: ERROR: Server replied with a response that violates the IMAP protocol

018-09-18 07:36:26,070 - Thread-mail_example.de_mx1 - DEBUG: IMAP IDLE response: []
2018-09-18 07:36:26,082 - Thread-mail_example.de_mx1 - DEBUG: < b' Still here'
2018-09-18 07:36:26,083 - Thread-mail_example.de_mx1 - ERROR: ERROR: Server replied with a response that violates the IMAP protocol

2018-09-18 20:20:26,817 - Thread-mail_example.de_mx2 - DEBUG: IMAP IDLE response: []
2018-09-18 20:20:26,830 - Thread-mail_example.de_mx2 - DEBUG: < b'till here'
2018-09-18 20:20:26,830 - Thread-mail_example.de_mx2 - ERROR: ERROR: Server replied with a response that violates the IMAP protocol

2018-09-18 20:16:26,090 - Thread-mail_test.de_mx1 - DEBUG: IMAP IDLE response: []
2018-09-18 20:16:26,105 - Thread-mail_test.de_mx1 - DEBUG: < b''
2018-09-18 20:16:26,106 - Thread-mail_test.de_mx1 - ERROR: ERROR: Server replied with a response that violates the IMAP protocol

2018-09-18 20:20:26,752 - Thread-mail_test.de_mx2 - DEBUG: IMAP IDLE response: []
2018-09-18 20:20:26,764 - Thread-mail_test.de_mx2 - DEBUG: < b'l here'
2018-09-18 20:20:26,765 - Thread-mail_test.de_mx2 - ERROR: ERROR: Server replied with a response that violates the IMAP protocol

[OnnoH]

I get this exception when I issue a NOOP command to Gmail:

2020-07-14 14:22:49,616 - imapclient.imaplib - DEBUG - > b'BCLH7 NOOP'
2020-07-14 14:22:49,741 - imapclient.imaplib - DEBUG - < b'BCLH6 BAD Could not parse command'
2020-07-14 14:22:49,741 - imapclient.imaplib - DEBUG - 	matched b'(?P<tag>BCLH\\d+) (?P<type>[A-Z]+) (?P<data>.*)' => (b'BCLH6', b'BAD', b'Could not parse command')
2020-07-14 14:22:49,741 - imapclient.imaplib - DEBUG - BAD response: b'Could not parse command'
2020-07-14 14:22:49,741 - imapclient.imaplib - DEBUG - > b'BCLH8 LOGOUT'

[OnnoH]

And something else with Outlook.com:

2020-07-14 16:42:14,223 - imapclient.imaplib - DEBUG - > b'FONL7 NOOP'
2020-07-14 16:42:14,251 - imapclient.imaplib - DEBUG - < b'FONL7 BAD Command received in Invalid state.'
2020-07-14 16:42:14,251 - imapclient.imaplib - DEBUG - 	matched b'(?P<tag>FONL\\d+) (?P<type>[A-Z]+) (?P<data>.*)' => (b'FONL7', b'BAD', b'Command received in Invalid state.')
2020-07-14 16:42:14,251 - imapclient.imaplib - DEBUG - BAD response: b'Command received in Invalid state.'
2020-07-14 16:42:14,251 - imapclient.imaplib - DEBUG - > b'FONL8 LOGOUT'

[mjs]

It seems like you might be calling NOOP while idling. Is that possible? You need stop idling by calling idle_done before any other commands can be issued (including NOOP).

[mjs]

It would be useful if you could provide a minimal code example that triggers the problem.

[mjs]

Closing due to inactivity. Please reopen if this is still a problem for you and you are able to provide more detail.