Mail-in-a-Box DNS resolution stopped working

Help with Setup/Upgrade
1

I’ve been running MIB on a VPS on Contabo with the domain registered through Gandi dot net using glue record since March 2026 - Nothing has changed at Gandi, and there have been two upgrades to MIB.

Today my Mail client has been unable to connect, the domain name does not resolve.

SSH into the box, I cannot resolve any hostnames. I can’t run apt update or mailinabox. All conf files look fine.

systemd-resolved, nsd and named are running.

I can bring up mailinabox admin using IP address, but status won’t run (cause of DNS resolution I assume)

I can use dig +tcp @1 . 1 . 1 . 1 domain.name successfully.

I have rebooted - I have searched these forums as well as many others - the closest thing was on this forum under dns-stopped-working-related-to-glue-records/6840 (new users can’t post links) but my box does not list as a serverHold as his did, and his solution was to used a different domain name. I would prefer to fix this issue (whatever it is).

My last resort has been to post here hoping someone can point me in the right direction.

Thanks!

2

It looks like my original post was 4 hours or so ago. I had a session and as soon as the band left I closed Pro Tools and loaded up my mailer and browsers - lo and behold - it fixed itself?

I’m now running apt update && apt upgrade -y and mailinabox followed by a reboot.

What worried me most while the box wasn’t resolving is that watching the mail.log, I could see the RBL lookups failing - I don’t know how those other mail servers were finding me while my domain didn’t resolve (cause my authoritative name server was down) - but, not being able to do RBL lookups or even hostnames for that matter wasn’t helping mail flow or not.

I really wish I knew where the problem was.

Gandi dot Net (registrar), Contabo VPS (although I could ssh into the server just fine), or mailinabox’s authoritative name server.