[mailop] SMTP disconnect… (Was: Hosteurope contact?)

[Thomas Walter via mailop]

Hello,




I can't find an RBL check to confirm that. The following two say, it is not:

https://tinycp.com/page/show/rbl-check
https://whois.smartweb.cz/en/blacklist/check/212.201.120.206/

And it is not listed anywhere else either

https://mxtoolbox.com/SuperTool.aspx?action=blacklist%3a212.201.120.206&run=toolpage





May  6 23:53:54 mx-out-02 postfix/smtp[14561]:
36119E0288: to=<xxx>, relay=mx0.webpack.hosteurope.de[80.237.138.5]:25,
delay=306795, delays=306794/0.17/0.18/0, dsn=4.4.2,
status=deferred (lost connection with
mx0.webpack.hosteurope.de[80.237.138.5] while performing the HELO
handshake)

Turns out

mx-out-02:~$ nc mx0.webpack.hosteurope.de 25

ehlo mx-out-02.fh-muenster.de
550-REJECT: 212.201.120.206 is in csi.cloudmark.com :

550 Remediation Portal https://csi.cloudmark.com/en/reset (ID:550:3:0)
mx-out-02:~$



https://www.rfc-editor.org/rfc/rfc5321#section-4.1.1.10

4.1.1.10.  QUIT (QUIT)

   This command specifies that the receiver MUST send a "221 OK" reply,
   and then close the transmission channel.

   The receiver MUST NOT intentionally close the transmission channel
   until it receives and replies to a QUIT command (even if there was an
   error).

Or is there a new version to the standards that allows this?

Regards
Thomas Walter

--
Thomas Walter
Datenverarbeitungszentrale

FH Münster
- University of Applied Sciences -
Corrensstr. 25, Raum B 112
48149 Münster

Tel: +49 251 83 64 908
Fax: +49 251 83 64 910
www.fh-muenster.de/dvz/

according to replies from Hosteurope it turns out our server with 212.201.120.206 is listed on csi.cloudmark.com. I just tried to have it removed anyway, since it seems to be the only way to fix this. Either way, I was irritated, why we don't get a proper 5xx status code in our logs, but just 220 mx0.webpack.hosteurope.de ESMTP (mi005.mc1.hosteurope.de) (even more power) Sun, 07 May 2023 00:03:13 +0200 550-Listed as Poor Reputation Sender. Cloudmark Sender Intelligence Reputation All this trying to figure out what's going wrong, contacting support, etc. could've been avoided if they followed the RFC?

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