Not receiving any inbound traffic on ports 53 or 25

[DrPizza]

I have a static /29. On one machine I host a mail server, and on another a DNS server.

I have appropriate firewall rules (TomatoUSB firewall, using iptables) to forward traffic to machines on my LAN. Other firewall walls (including HTTP, HTTPS, IMAP, etc.) are working fine.

Until yesterday or thereabouts, everything worked fine. For the last 24 hours or so, the rules for SMTP (port 25) and DNS (port 53, both UDP and TCP) have not seen any traffic. It's not hitting the firewall, much less being dropped.

Is there some upstream filtering going on?

[DrPizza]

Welp. OK so DNS was my fault (a VM that should have been up wasn't up). But SMTP is not.