==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): latest
- Deployed with iRedMail Easy or the downloadable installer? downloadable
- Linux/BSD distribution name and version: ubuntu 18.04
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): LDAP
- Web server (Apache or Nginx): nginx
- Manage mail accounts with iRedAdmin-Pro? no
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====
Hello i do a stupid thing, i delete   f2b-postfix rules ....

Chain f2b-postfix (1 references)
num  target     prot opt source               destination         

Chain f2b-postfix-pregreet (1 references)
num  target     prot opt source               destination         
1    REJECT     all  --  net6-ip139.linkbg.com  anywhere             reject-with icmp-port-unreachable
2    RETURN     all  --  anywhere             anywhere           

How can i come back to the normal config
Thanks a lot