Error 421 - error reading data

1

Hello everyone,
After installing Axigen on Ubuntu Server 24.04, I am able to send emails but the SMTP receiving is not working. In the everything log I noticed an error messages like:

2024-10-16 16:07:54 +0000 08 mydomain SMTP-IN:00000028: [192.168.0.15:25] connection accepted from [40.92.48.34:18240]
2024-10-16 16:07:54 +0000 16 mydomain SMTP-IN:00000028: >> 220 mydomain.com Axigen ESMTP ready
2024-10-16 16:07:54 +0000 16 mydomain SMTP-IN:00000028: >> 421 mydomain.com error reading data
2024-10-16 16:07:54 +0000 08 mydomain SMTP-IN:00000028: closing session from [40.92.48.34]

The port forwarding for the network segment is working correctly since if other services are listening on port 465 or 25 everything is working as expected.

I will appreciate any suggestion where I can find more information for this error.

Thanks!

2

Hello,

What you have posted is showing that Axigen is sending the SMTP banner (220) but didn’t received the EHLO command from remote party.

Because the next line is showing code 421 and error reading data I could only assume that a network device between Axigen and remote party is dropping the connection so please double check if there are no special rules that may block ingress connections on port 25 to your server.

Just to check that all is fine on your server you may open a terminal and check the response via a comand like:

$ telnet 192.168.0.15 25
220 mydomain.com Axigen ESMTP ready
ehlo test
250-mydomain.com Axigen ESMTP hello
250-PIPELINING
250-8BITMIME
250-BINARYMIME
250-CHUNKING
250-SIZE 31457280
250-STARTTLS
250-HELP
250 OK
quit
221-mydomain.com Axigen ESMTP is closing connection
221 Good bye
Connection closed by foreign host.

If the telnet session is dropped immediately after the 220 banner line than something is wrong on your server (which is not what we expect) and please share the Axigen logs for this session (keep Protocol Communication log level for SMTP Receiving service).

HTH,
Ioan

3

I installed Axigen on a WIndows host and have the same issue. Seems that the problem could be related to a FW somewhere in the infrastructure, but I will have to investigate this.

This is the part of the log, for the session:

2024-10-16 21:11:44 +0300 08 TZOKEV SMTP-IN:00000049: [192.168.1.133:25] connection accepted from [185.70.40.140:14939]
2024-10-16 21:11:44 +0300 08 TZOKEV SMTP-IN:00000049: closing session from [185.70.40.140]
2024-10-16 21:11:45 +0300 08 TZOKEV SMTP-IN:0000004A: [192.168.1.133:25] connection accepted from [51.77.79.158:33329]
2024-10-16 21:11:45 +0300 08 TZOKEV SMTP-IN:0000004A: closing session from [51.77.79.158]
2024-10-16 21:11:45 +0300 08 TZOKEV SMTP-IN:0000004B: [192.168.1.133:25] connection accepted from [185.70.43.21:61619]
2024-10-16 21:11:45 +0300 08 TZOKEV SMTP-IN:0000004B: closing session from [185.70.43.21]
2024-10-16 21:11:49 +0300 08 TZOKEV SMTP-IN:0000004C: [192.168.1.133:25] connection accepted from [40.92.90.91:14912]
2024-10-16 21:11:49 +0300 08 TZOKEV SMTP-IN:0000004C: closing session from [40.92.90.91]

4

The issue was a configuration on a FW that resets the session, which was very frustrating. Now everything is working properly.

1 Like