NoneType object has no attribute connection_state

[Andi-bz]

Hi,

I get this error when I want to send an email from Siemens Runtime Advanced

PS C:\email-oauth2-proxy-main> python .\emailproxy.py --debug
2022-11-27 09:52:23: Initialising Email OAuth 2.0 Proxy from config file C:\email-oauth2-proxy-main\emailproxy.config
2022-11-27 09:52:23: Starting SMTP server at localhost:2465 (unsecured) proxying smtp.gmail.com:587 (STARTTLS)
2022-11-27 09:52:23: Initialised Email OAuth 2.0 Proxy - listening for authentication requests. Connect your email client to begin
2022-11-27 09:52:25: New incoming connection to SMTP server at localhost:2465 (unsecured) proxying smtp.gmail.com:587 (STARTTLS)
2022-11-27 09:52:25: Accepting new connection to SMTP server at localhost:2465 (unsecured) proxying smtp.gmail.com:587 (STARTTLS) via ('127.0.0.1', 61039)
2022-11-27 09:52:25: SMTP (localhost:2465; 127.0.0.1:61039->smtp.gmail.com:587) --> [ Client connected ]
2022-11-27 09:52:25: SMTP (localhost:2465; 127.0.0.1:61039->smtp.gmail.com:587)     <-- b'220 smtp.gmail.com ESMTP t13-20020a05600c198d00b003cf54b77bfesm17481012wmq.28 - gsmtp\r\n'
2022-11-27 09:52:25: SMTP (localhost:2465; 127.0.0.1:61039->smtp.gmail.com:587) <-- b'220 smtp.gmail.com ESMTP t13-20020a05600c198d00b003cf54b77bfesm17481012wmq.28 - gsmtp\r\n'
2022-11-27 09:52:25: SMTP (localhost:2465; 127.0.0.1:61039->smtp.gmail.com:587) --> b'EHLO localhost\r\n'
2022-11-27 09:52:25: SMTP (localhost:2465; 127.0.0.1:61039->smtp.gmail.com:587)     --> b'EHLO localhost\r\n'
2022-11-27 09:52:26: SMTP (localhost:2465; 127.0.0.1:61039->smtp.gmail.com:587)     <-- b'250-smtp.gmail.com at your service, [195.233.233.233]\r\n'
2022-11-27 09:52:26: SMTP (localhost:2465; 127.0.0.1:61039->smtp.gmail.com:587)     <-- b'250-SIZE 35882577\r\n'
2022-11-27 09:52:26: SMTP (localhost:2465; 127.0.0.1:61039->smtp.gmail.com:587)     <-- b'250-8BITMIME\r\n'
2022-11-27 09:52:26: SMTP (localhost:2465; 127.0.0.1:61039->smtp.gmail.com:587)     <-- b'250-STARTTLS\r\n'
2022-11-27 09:52:26: SMTP (localhost:2465; 127.0.0.1:61039->smtp.gmail.com:587)     <-- b'250-ENHANCEDSTATUSCODES\r\n'
2022-11-27 09:52:26: SMTP (localhost:2465; 127.0.0.1:61039->smtp.gmail.com:587)     <-- b'250-PIPELINING\r\n'
2022-11-27 09:52:26: SMTP (localhost:2465; 127.0.0.1:61039->smtp.gmail.com:587)     <-- b'250-CHUNKING\r\n'
2022-11-27 09:52:26: SMTP (localhost:2465; 127.0.0.1:61039->smtp.gmail.com:587)     <-- b'250 SMTPUTF8\r\n'
2022-11-27 09:52:26: SMTP (localhost:2465; 127.0.0.1:61039->smtp.gmail.com:587)     --> b'STARTTLS\r\n'
2022-11-27 09:52:26: SMTP (localhost:2465; 127.0.0.1:61039->smtp.gmail.com:587)     <-- b'220 2.0.0 Ready to start TLS\r\n'
2022-11-27 09:52:26: SMTP (localhost:2465; 127.0.0.1:61039->smtp.gmail.com:587) <-> [ Starting TLS handshake ]
2022-11-27 09:52:26: SMTP (localhost:2465; 127.0.0.1:61039->smtp.gmail.com:587) [ Successfully negotiated SMTP STARTTLS connection - re-sending greeting ]
2022-11-27 09:52:26: SMTP (localhost:2465; 127.0.0.1:61039->smtp.gmail.com:587)     --> b'EHLO localhost\r\n'
2022-11-27 09:52:26: SMTP (localhost:2465; 127.0.0.1:61039->smtp.gmail.com:587) <-> [ TLS handshake complete ]
2022-11-27 09:52:26: SMTP (localhost:2465; 127.0.0.1:61039->smtp.gmail.com:587)     <-- b'250-smtp.gmail.com at your service, [195.233.233.233]\r\n'
2022-11-27 09:52:26: SMTP (localhost:2465; 127.0.0.1:61039->smtp.gmail.com:587) <-- b'250-smtp.gmail.com at your service, [195.233.233.233]\r\n'
2022-11-27 09:52:26: SMTP (localhost:2465; 127.0.0.1:61039->smtp.gmail.com:587)     <-- b'250-SIZE 35882577\r\n'
2022-11-27 09:52:26: SMTP (localhost:2465; 127.0.0.1:61039->smtp.gmail.com:587) <-- b'250-SIZE 35882577\r\n'
2022-11-27 09:52:26: SMTP (localhost:2465; 127.0.0.1:61039->smtp.gmail.com:587)     <-- b'250-8BITMIME\r\n'
2022-11-27 09:52:26: SMTP (localhost:2465; 127.0.0.1:61039->smtp.gmail.com:587) <-- b'250-8BITMIME\r\n'
2022-11-27 09:52:26: SMTP (localhost:2465; 127.0.0.1:61039->smtp.gmail.com:587)     <-- b'250-AUTH LOGIN PLAIN XOAUTH2 PLAIN-CLIENTTOKEN OAUTHBEARER XOAUTH\r\n'
2022-11-27 09:52:26: SMTP (localhost:2465; 127.0.0.1:61039->smtp.gmail.com:587) <-- b'250-AUTH PLAIN LOGIN\r\n'
2022-11-27 09:52:26: SMTP (localhost:2465; 127.0.0.1:61039->smtp.gmail.com:587) --> [ Client disconnected ]
2022-11-27 09:52:26: SMTP (localhost:2465; 127.0.0.1:61039->smtp.gmail.com:587)     <-- b'250-ENHANCEDSTATUSCODES\r\n'
2022-11-27 09:52:26: SMTP (localhost:2465; 127.0.0.1:61039->smtp.gmail.com:587) Caught asyncore info message (server) - error : uncaptured python exception, closing channel <__main__.SMTPOAuth2ServerConnection smtp.gmail.com:587 at 0x19fa067b8b0> (<class 'AttributeError'>:'NoneType' object has no attribute 'connection_state' [C:\Program Files\WindowsApps\PythonSoftwareFoundation.Python.3.10_3.10.2288.0_x64__qbz5n2kfra8p0\lib\asyncore.py|read|90] [C:\email-oauth2-proxy-main\emailproxy.py|handle_read_event|807] [C:\Program Files\WindowsApps\PythonSoftwareFoundation.Python.3.10_3.10.2288.0_x64__qbz5n2kfra8p0\lib\asyncore.py|handle_read_event|427] [C:\email-oauth2-proxy-main\emailproxy.py|handle_read|1352] [C:\email-oauth2-proxy-main\emailproxy.py|process_data|1546])
2022-11-27 09:52:26: SMTP (localhost:2465; 127.0.0.1:61039->smtp.gmail.com:587) <-- [ Server disconnected ]

Thanks

[simonrob]

The reason for this is that your client is disconnecting when it receives the EHLO response 250-AUTH PLAIN LOGIN, probably because it doesn't support these methods (or has to have them enabled explicitly as it sees them as insecure).

The proxy could hide/suppress these type of errors, but at the moment it is normally better to show them as a way to highlight connection issues such as this one. The proxy continues running regardless; this is just a warning, and the issue is with your client.