Mailinabox behind NAT virtualmin/webmin on front

Hello MIAB experts,

I’m running Mailinabox behind NAT on a second server which is on the same network of the first server with domain name mailer.mydomain.com (192.168.1.6)

MIAB system status checks read:

:heavy_multiplication_x:
Public DNS (nsd4) is not running (port 53).

:heavy_multiplication_x:
Incoming Mail (SMTP/postfix) is running but is not publicly accessible at xxx.xx.xx.xxx:25.

:heavy_multiplication_x:
IMAPS (dovecot) is running but is not publicly accessible at xxx.xx.xx.xxx:993.

I turned off the postfix and dovecot on virtualmin, but still not working. any idea?

Make sure ports 25, 587, 143, and 993 are open on the firewall and pointing to the internal IP address of MIAB.

Port 53 (TCP and UDP!) is optional, use only if you are using MIAB as a nameserver / DNS host.