Send Error Connection refused (os error 111)

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1

Hi teams

How do I get the type of os error 111, which makes it easier for me to troubleshoot errors.

3

kumo version : Release 2025.05.06-b29689af

[
    {
        "recipient": "xxx@xxx.com",
        "response": {
            "content": "KumoMTA internal: failed to connect to any candidate hosts: connect to 111.124.203.44:25 and read initial banner: failed to connect to 10.168.20.50:6000 Socks5 { server: 10.168.20.50:6000, source: 58.220.14.188, destination: 111.124.203.44:25, username_and_password: None }: Connection refused (os error 111), connect to 111.124.203.44:25 and read initial banner: failed to connect to 10.168.20.50:6000 Socks5 { server: 10.168.20.50:6000, source: 58.220.14.188, destination: 111.124.203.44:25, username_and_password: None }: Connection refused (os error 111), connect to 111.124.203.44:25 and read initial banner: failed to connect to 10.168.20.50:6000 Socks5 { server: 10.168.20.50:6000, source: 58.220.14.188, destination: 111.124.203.44:25, username_and_password: None }: Connection refused (os error 111), connect to 111.124.203.44:25 and read initial banner: failed to connect to 10.168.20.50:6000 Socks5 { server: 10.168.20.50:6000, source: 58.220.14.188, destination: 111.124.203.44:25, username_and_password: None }: Connection refused (os error 111)",
            "code": 400
        },
        "site": "xxx->(126mx01|126mx02|126mx03|126mx00).mxmail.netease.com@smtp_client",
        "delivery_protocol": "ESMTP",
        "created": 1749004844,
        "nodeid": "77a6fd6d-470e-4456-83c3-68aa67c681ea",
        "queue": "xxx@xxx.com",
        "sender": "xx@campaign.xx.com.cn",
        "timestamp": 1749022877,
        "id": "4fef2ac640ed11f09feabc241172448d",
        "egress_source": "xx",
        "num_attempts": 4,
        "headers": {},
        "egress_pool": "xx",
        "meta": {
            
        },
        "type": "TransientFailure",
        "reception_protocol": "ESMTP",
        "bounce_classification": "Uncategorized",
        "size": 0,
        "session_id": "37466c2c-1a57-4e64-89b9-55f42976f151"
    }

]
4

The answer is in the error message .
Connection refused (os error 111)
This is an os level error not KumoMTA

5

https://cdmiweb.com/LinuxOS-Error-Codes.html

6

OK, Yesterday, the customer sent 300,000 emails in a concentrated manner. When sending to 5,000, this error occurred due to the high failure rate or high frequency of ISP feedback. However, other tenants send it normally. I am not sure if it will continue to send it in a certain time period in the future. It was sent using momentum before. KUMOMTA used the same IP and the speed limit configuration was the same. The momentum did not have such a high soft bullet. I’ll continue to observe the situation.

7

Ten hours have passed, and the retries have failed. No one is successful. Do I need to restart the socks5 service?

8

It was solved that the maximum number of files opened by socks server exceeded :joy:

9

yep, that will do it. You should set up the proxy with the same os configuration yuou set up LumoMTA - adjust the OS params appropriately.