Roundcube

Long-standing open-source webmail client (IMAP-based).

Visit Roundcube Start free with MailKite

How MailKite fits

MailKite ships @mailkite/mail — an MIT-licensed, embeddable webmail component for React, if you'd rather not run PHP.

Receive email into Roundcube via MailKite

A minimal, copy-paste starter. Swap in your own domain and API key.

webhook.ts

import { verifyWebhook } from "@mailkite/client";

// MailKite POSTs every inbound email at your domain as JSON.
// Point a route at this handler in the MailKite dashboard.
export default async function handler(req: Request) {
  const raw = await req.text();
  const sig = req.headers.get("x-mailkite-signature") ?? "";

  // Reject anything not signed by your webhook secret
  const ok = await verifyWebhook(sig, raw, process.env.MK_WEBHOOK_SECRET!);
  if (!ok) return new Response("bad signature", { status: 401 });

  const email = JSON.parse(raw);
  // Route into Roundcube: open a ticket, create a task, store a record
  await routeIntoName(email);   // email.from · email.subject · email.text

  return new Response(JSON.stringify({ ok: true }));
}

Read the inbound webhooks guide

Roundcube is a widely-deployed open-source webmail client written in PHP that reads IMAP mailboxes. It's the classic choice for teams self-hosting mail who need a familiar, no-frills webmail UI for reading and sending. Mature and stable, though the UX predates modern web apps.