IP Blocked but can not found in blacklist

[hoanv9]

Dear all,
I am using DNSBL as bellow
zen.spamhaus.org*3 bl.mailspike.net*3 b.barracudacentral.org*2 ix.dnsbl.manitu.net

Few days ago, lots of email was blocked due to blacklisted, the log is

Oct 6 09:24:59 proxmox postfix/postscreen[1640998]: NOQUEUE: reject: RCPT from [40.107.236.41]:12960: 550 5.7.1 Service unavailable; client [40.107.236.41] blocked using b.barracudacentral.org; from=<sender@sender.com>, to=<receiver@mydomain.com>, proto=ESMTP, helo=<NAM11-BN8-obe.outbound.protection.outlook.com>

I've checked in many blacklist checker site, but can not find that IP was blocked https://mxtoolbox.com/SuperTool.aspx?action=blacklist:40.107.236.41&run=toolpage
There are no result in https://barracudacentral.org/lookups/lookup-reputation

Is there any missing in my configuration?
Thanks.

 

[Stoiko Ivanov]

it could be that your local DNS-server is returning wrong answers - check dns-resolution on your PMG and the config of the used DNS-server

 

[hoanv9]

I used DNS by following https://pmg.proxmox.com/wiki/index.php/DNS_server_on_Proxmox_Mail_Gateway
Could you please to share how to check the dns resolution>?

 

[Stoiko Ivanov]

see for example:
https://forum.proxmox.com/threads/spamhaus-not-working-on-fresh-install.115198/post-498104

use dig

see also:
https://barracudacentral.org/rbl/how-to-use