Email forwarding

"records": {
  "MX": [
    { "priority": 10, "value": "mx1.improvmx.com" },
    { "priority": 20, "value": "mx2.improvmx.com" }
  ]
}

mx1.improvmx.com and mx2.improvmx.com at priorities 10 and 20 are ImprovMX's standard mail servers, the same for every domain. MX may coexist with A and TXT at the same name, so this is safe to add even if you also point you.runs-on.dev at a site.

Two ways to apply this. The quickest is runs-on.dev/manage: sign in, pick the record type, paste the value, save. It writes the same commit to the registry and DNS follows within seconds. The steps below do it by pull request instead, which is what you want if you would rather review the change first. Either way handles subdomains entries.

1. At improvmx.com, add you.runs-on.dev as a domain and set up a forwarding alias (for example, *@you.runs-on.dev → your real address).
2. Fork the registry and edit domains/you.json to the record above.
3. Open a pull request. Once merged, the MX records are synced to DNS automatically.

Providers that sign outgoing mail — Zoho Mail, Google Workspace — ask for one more TXT record at a selector hostname, which DKIM verification reads. The selector is the provider's choice (Zoho uses zmail, Google uses google), so the registry accepts any selector in the <selector>._domainkey label form, published under subdomains:

"subdomains": {
  "zmail._domainkey": { "TXT": ["v=DKIM1; k=rsa; p=YOUR-PROVIDERS-KEY"] }
}

Copy the selector and key exactly from your provider's DKIM page. A TXT on a subdomain coexists with the MX records above, so signing and forwarding work on the same name.

ImprovMX's dashboard shows the domain as verified once it can see both MX records. Send a test email to your you.runs-on.dev address and confirm it lands in the forwarded inbox, usually within a minute.