function promises.resolveMx
Usage in Deno
```typescript import { promises } from "node:node__dns.d.ts"; ```
resolveMx(hostname: string): Promise<MxRecord[]>
Uses the DNS protocol to resolve mail exchange records (`MX` records) for the `hostname`. On success, the `Promise` is resolved with an array of objects
containing both a `priority` and `exchange` property (e.g.`[{priority: 10, exchange: 'mx.example.com'}, ...]`).
Promise<MxRecord[]>