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Server disconnected when SMTP proxy on another computer

See original GitHub issue

EDIT: When I disabled the signature then message was sent as it should.

So the problem is not because the proxy is on another computer - the problem must be with parsing the signature HTML which looks like:

<html>
<body>
<font size=1 color="#0000FF"><br>
</font><img src="file://C:\imgs\signature.gif" width=18 height=18 alt="sig"><font face="Comic Sans MS" color="#0000FF">&nbsp;<b><i>My name</i></b></font>&nbsp; <img src="file://C:\imgs\sig.gif" width=18 height=18 alt="sig"><br></body>
</html>

or maybe with sending the .gifs which are part of the signature.

END OF EDIT

Hello again,

in the meantime while still testing running the proxy on Windows XP I’ve made a temporary setup where the proxy runs on Windows 10 computer which is in the same local network as the Windows XP computer running Eudora email client and has static IP.

I didn’t expect problems but while receiving email via POP + gmail works well, sending via SMTP + gmail never gets to the end when the proxy is on another computer - the progress bar in Eudora email client always stops at almost the end and after a while there is an error:

Error reading from network
Cause: connection aborted due to timeout or other failure (10053)

I saw issue #36 even before setting up the proxy on another computer and I did set local_address for both POP and SMTP and the log looks right until communication just stops.

I’ve compared the logs from the working case where SMTP server is on the same computer as email client with the logs where the proxy is on another computer and everything looks the same except in the case where the proxy is on another computer the server (gmail) suddenly disconnects. Here is how the logs look like at the point where disconnect happens:

.
.
.
2022-08-15 23:26:14,505: SMTP (192.168.1.102:1465; 192.168.1.100:3838->smtp.gmail.com:465; [[ email address removed ]]@gmail.com) --> b'RCPT TO:<[[ email address removed ]]@yahoo.com>\r\n'
2022-08-15 23:26:14,557: SMTP (192.168.1.102:1465; 192.168.1.100:3838->smtp.gmail.com:465; [[ email address removed ]]@gmail.com) <-- b'250 2.1.5 OK [[ some numbers removed ]] - gsmtp\r\n'
2022-08-15 23:26:14,559: SMTP (192.168.1.102:1465; 192.168.1.100:3838->smtp.gmail.com:465; [[ email address removed ]]@gmail.com) --> b'DATA\r\n'
2022-08-15 23:26:14,664: SMTP (192.168.1.102:1465; 192.168.1.100:3838->smtp.gmail.com:465; [[ email address removed ]]@gmail.com) <-- b'354  Go ahead [[ some numbers removed ]] - gsmtp\r\n'
2022-08-15 23:26:14,666: SMTP (192.168.1.102:1465; 192.168.1.100:3838->smtp.gmail.com:465; [[ email address removed ]]@gmail.com) --> b'X-Mailer: QUALCOMM Windows Eudora Version 7.1.0.9\r\n'
2022-08-15 23:36:14,716: SMTP (192.168.1.102:1465; 192.168.1.100:3838->smtp.gmail.com:465; [[ email address removed ]]@gmail.com) <-- [ Server disconnected ]

192.168.1.100 is Windows XP computer with Eudora email client 192.168.1.102 is Windows 10 computer running Email OAuth2 Proxy

I configured the proxy with:

[SMTP-1465]
local_address = 192.168.1.102
server_address = smtp.gmail.com
server_port = 465

[POP-1996]
local_address = 192.168.1.102
server_address = pop.gmail.com
server_port = 995

I am using the most recent code and have tried to disable the firewalls but still the same.

The last line Eudora sends is always:

2022-08-15 23:26:14,666: SMTP (192.168.1.102:1465; 192.168.1.100:3838->smtp.gmail.com:465; [[ email address removed ]]@gmail.com) --> b'X-Mailer: QUALCOMM Windows Eudora Version 7.1.0.9\r\n'

while in the working configuraton (where the proxy and the email client are on the same computer) these lines look like:

2022-08-15 23:34:27,787: SMTP (localhost:1465; 127.0.0.1:49213->smtp.gmail.com:465; [[ email address removed ]]@gmail.com) --> b'X-Mailer: QUALCOMM Windows Eudora Version 7.1.0.9\r\n'
2022-08-15 23:34:27,803: SMTP (localhost:1465; 127.0.0.1:49213->smtp.gmail.com:465; [[ email address removed ]]@gmail.com) --> b'Date: Mon, 15 Aug 2022 23:34:21 +0200\r\nTo: [[ email address removed ]]@yahoo.com\r\nFrom: "Name" <[[ email address removed ]]@gmail.com>\r\nSubject: Some subject\r\nMime-Version: 1.0\r\nContent-Type: text/plain; charset="us-ascii"; format=flowed\r\n\r\nMessage body\r\n\r\n.\r\n'
2022-08-15 23:34:28,412: SMTP (localhost:1465; 127.0.0.1:49213->smtp.gmail.com:465; [[ email address removed ]]@gmail.com) <-- b'250 2.0.0 OK  [[ some numbers removed ]] - gsmtp\r\n'
2022-08-15 23:34:28,428: SMTP (localhost:1465; 127.0.0.1:49213->smtp.gmail.com:465; [[ email address removed ]]@gmail.com) --> b'QUIT\r\n'
2022-08-15 23:34:28,475: SMTP (localhost:1465; 127.0.0.1:49213->smtp.gmail.com:465; [[ email address removed ]]@gmail.com) <-- b'221 2.0.0 closing connection [[ some numbers removed ]] - gsmtp\r\n'
2022-08-15 23:34:28,475: SMTP (localhost:1465; 127.0.0.1:49213->smtp.gmail.com:465; [[ email address removed ]]@gmail.com) <-- [ Server disconnected ]

This is what is logged by Eudora when trying to send an email:

MAIN    16: 1.44 Preparing messages to Send: 1
MAIN    16: 1.55 RSET
MAIN    16: 1.55 MAIL FROM:<removed@gmail.com>
MAIN    16: 1.55 RCPT TO:<removed@yahoo.com>
MAIN    16: 1.55 DATA
MAIN    16: 1.55 Test
MAIN    16: 1.55 Sending file "C:\imgs\signature.gif"...
MAIN    16: 1.55 Test
MAIN    16: 1.55 Preparing messages to Send: 0
4776    16: 1.55 Open 192.168.1.102:1465
4776     8: 2.34 Dialog: "Error reading from network\r\n"
4776     8: 2.34 Dialog: "\r\n"
4776     8: 2.34 Dialog: "Cause: connection aborted due to timeout or other failure (10053)"

And this is what is logged by Eudora in working configuration where the proxy and the email client are on the same computer:

MAIN    16: 0.00 Preparing messages to Send: 1
MAIN    16: 0.00 RSET
MAIN    16: 0.00 MAIL FROM:<removed@gmail.com>
MAIN    16: 0.00 RCPT TO:<removed@yahoo.com>
MAIN    16: 0.00 DATA
MAIN    16: 0.00 Message subject
MAIN    16: 0.00 Preparing messages to Send: 0
1088    16: 0.00 Open 127.0.0.1:1465

Issue Analytics

State:
Created a year ago
Comments:19 (7 by maintainers)

Top GitHub Comments

1reaction

chupocrocommented, Sep 2, 2022

I agree. You may close this issue. I will still continue to investigate the cause of the problem and report back when/if I find something useful.

0reactions

simonrobcommented, Sep 1, 2022

I just did a test to check if maybe some file from email client installation is missing or damaged. I created a new Windows XP virtual machine and transfered the whole folder containing the email client from the PC where email client is running to VM and in that case the email with the attachment was sent without problems.

I think that underlying all of this there is the issue that Windows XP was released well before all of the current standard secure connection protocols were in use, and the workarounds to give it this capability are perhaps not totally reliable. I’m supportive of using the proxy to enable continued use of obsoleted devices/apps, but there are lower level things that it cannot help with.

Given that the issue here does not happen in a VM, and that it hasn’t been possible to replicate it outside of the problematic setup so far, I think it might be time to put this to rest. I don’t think there’s any evidence that this issue is caused by the proxy at least.