==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release):  1.4.2
- Deployed with iRedMail Easy or the downloadable installer? downloadable installer
- Linux/BSD distribution name and version: ubuntu 20.04
- Store mail accounts in which backend (LDAP/MySQL/PGSQL):  MySQL
- Web server (Apache or Nginx): Nginx
- Manage mail accounts with iRedAdmin-Pro? Yes
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====

I found alot of DNS qureies for spamhaus and b.barracudacentral.org with strange IPs ,, all response is Host not found, try again !! ,, why and how this qureies work and what is correct answer ?!

logs here :
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Mar 28 11:14:48 email postfix/dnsblog[2476903]: warning: dnsblog_query: lookup error for DNS query 21.211.83.41.zen.spamhaus.org: Host or domain name not found. Name service error for name=21.211.83.41.zen.spamhaus.org type=A: Host not found, try again
123664  Mar 28 11:14:50 email postfix/postscreen[374415]: warning: dnsblog reply timeout 10s for zen.spamhaus.org
123674  Mar 28 11:14:50 email postfix/dnsblog[2344285]: warning: dnsblog_query: lookup error for DNS query 250.248.147.66.zen.spamhaus.org: Host or domain name not found. Name service error for name=250.248.147.66.zen.spamhaus.org type=A: Host not found, try again
123679  Mar 28 11:14:51 email postfix/postscreen[374415]: warning: dnsblog reply timeout 10s for zen.spamhaus.org

123822  Mar 28 11:15:04 email postfix/dnsblog[2422599]: warning: dnsblog_query: lookup error for DNS query 46.221.85.209.b.barracudacentral.org: Host or domain name not found. Name service error for name=46.221.85.209.b.barracudacentral.org type=A: Host not found, try again
124882  Mar 28 11:16:56 email postfix/dnsblog[2476693]: warning: dnsblog_query: lookup error for DNS query 46.221.85.209.zen.spamhaus.org: Host or domain name not found. Name service error for name=46.221.85.209.zen.spamhaus.org type=A: Host not found, try again
124883  Mar 28 11:16:56 email postfix/dnsblog[2476694]: warning: dnsblog_query: lookup error for DNS query 46.221.85.209.b.barracudacentral.org: Host or domain name not found. Name service error for name=46.221.85.209.b.barracudacentral.org type=A: Host not found, try again
126947  Mar 28 11:20:20 email postfix/dnsblog[2497978]: warning: dnsblog_query: lookup error for DNS query 46.221.85.209.zen.spamhaus.org: Host or domain name not found. Name service error for name=46.221.85.209.zen.spamhaus.org type=A: Host not found, try again
126952  Mar 28 11:20:20 email postfix/dnsblog[2497976]: warning: dnsblog_query: lookup error for DNS query 46.221.85.209.b.barracudacentral.org: Host or domain name not found. Name service error for name=46.221.85.209.b.barracudacentral.org type=A: Host not found, try again
129211  Mar 28 11:24:06 email postfix/dnsblog[2421530]: warning: dnsblog_query: lookup error for DNS query 46.221.85.209.zen.spamhaus.org: Host or domain name not found. Name service error for name=46.221.85.209.zen.spamhaus.org type=A: Host not found, try again
129212  Mar 28 11:24:06 email postfix/dnsblog[2421532]: warning: dnsblog_query: lookup error for DNS query 46.221.85.209.b.barracudacentral.org: Host or domain name not found. Name service error for name=46.221.85.209.b.barracudacentral.org type=A: Host not found, try again
130729  Mar 28 11:27:09 email postfix/dnsblog[2497976]: warning: dnsblog_query: lookup error for DNS query 46.221.85.209.b.barracudacentral.org: Host or domain name not found. Name service error for name=46.221.85.209.b.barracudacentral.org type=A: Host not found, try again
130733  Mar 28 11:27:09 email postfix/dnsblog[2497978]: warning: dnsblog_query: lookup error for DNS query 46.221.85.209.zen.spamhaus.org: Host or domain name not found. Name service error for name=46.221.85.209.zen.spamhaus.org type=A: Host not found, try again
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