Open
Description
Version
v20.15.0
Platform
linux & docker
Subsystem
dns
What steps will reproduce the bug?
I have this code:
const dns = require('dns');
const ign = dns.resolveMx("blek.cz", (err, addresses) => console.log([err, addresses]));
And results:
$ docker run -ti node:16 node
[ null, [ { exchange: 'blekmx1.blek.cz', priority: 100 } ] ]
$ docker run -ti node:18 node
[ null, [ { exchange: 'blek.cz', priority: 100 } ] ]
$ docker run -ti node:20 node
[ null, [ { exchange: 'blek.cz', priority: 100 } ] ]
$ docker run -ti node:20-alpine node
[ null, [ { exchange: 'blek.cz', priority: 100 } ] ]
$ docker run -ti node:22 node
[ null, [ { exchange: 'blekmx1.blek.cz', priority: 100 } ] ]
How often does it reproduce? Is there a required condition?
Might be system/resolver dependent. Also there should be something unusual about this particular domain
What is the expected behavior? Why is that the expected behavior?
$ dig +short mx blek.cz
100 blekmx1.blek.cz.
What do you see instead?
Bare "blek.cz" host even don't have SMTP port open so it makes emails undeliverable
Additional information
No response