MX 
MXToolbox
DNS, MX, blacklist, and deliverability lookup tools.
DNS, MX, blacklist, and deliverability lookup tools.
MailKite shows your domain's live SPF/DKIM/DMARC status in the dashboard and gates sending until DNS verifies.
A minimal, copy-paste starter. Swap in your own domain and API key.
import { MailKiteClient } from "@mailkite/client";
// One API, your own DKIM-signed domain — no mail server to run
const mailkite = new MailKiteClient({ token: process.env.MK_API_KEY! });
await mailkite.send({
from: "you@yourdomain.com", // any address on a verified domain
to: "user@example.com",
subject: "Hello from MXToolbox",
html: "<p>Sent in milliseconds via MailKite.</p>",
});MXToolbox is the widely-used suite of free lookup tools for email deliverability: MX records, DNS, SPF/DKIM/DMARC, blacklist checks, and SMTP diagnostics. It's a staple for anyone debugging why mail isn't arriving or checking their domain's reputation, alongside paid monitoring tiers.
Free tools + paid monitoring
Deliverability & DNS
SPF/DKIM/DMARC tools, inbox testing, and monitoring.
The lookup tools are free; ongoing monitoring and alerts are paid tiers.
Yes — MailKite verifies SPF/DKIM/DMARC at domain setup and shows live status in the dashboard; sending is gated until outbound DNS passes.
Point a domain, drop in a webhook URL, and send your first email in minutes. Unlimited domains, no credit card.
