Server works except fails System Status checks on ports and DNS

I am running a fresh install of Mail In A Box on Ubuntu 14.05 LTS. I own the server and it is installed in a local datacenter. I have a block of 5 public IPs. No ports are blocked by the ISP.

Mail In a Box is behind a firewall with an IP of It has its own public IP with 1:1 NAT and outbound NAT mappings for the local IP to go back out on the correct public IP. All of the ports shown in ufw are forwarded and verified open to the outside world.

I checked on my domain and absolutely everything checks out.

I am able to send and receive emails, use the webmail, web admin interface and access hosted on here as well.

In the System Status page I am seeing errors that all of the services are running but not accessible from the outside. It also says the nameserver glue records are incorrect, MX record not set, and A record not set. All of these things appear to be working but Mail In A Box says the do not. This is stopping me from provisioning certificates from Let’s Encrypt. I see:

DNS isn’t configured properly for this domain: DNS resolution failed (A: All nameservers failed to answer the query IN A: Server UDP port 53 answered SERVFAIL).

I am pretty sure this is a firewall related issue but I think everything is correct. I am positive this would work flawlessly if I put it outside of the firewall, but it would be nice not to do that if possible.

Does anyone have any suggestions for troubleshooting this?

Thank you!

I had the same problem with my box. This is the post that got it working: Status Checks Incorrect

Thanks arandomguy! That got me on the right track.

I found this specifically for pfSense which got the job done:'t_I_access_forwarded_ports_on_my_WAN_IP_from_my_LAN/OPTx_networks

That’s actually the same firewall I use. I’m glad to see I’m not the only one.

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