MailKaka vs MSG91

Built for one channel, not five. MSG91 spans SMS, WhatsApp, voice, and email under one account and credit system. If email is your main channel and you don't need the others, that breadth is overhead rather than a benefit.

A reply inbox built around email. MSG91 handles incoming email and replies, with a Unified Inbox on its wider platform. Every MailKaka domain ships with a shared team mailbox, without adopting a multichannel platform.

A familiar API if you're coming from a dev-first tool. MailKaka's send API mirrors Resend's request shape -- a common starting point for teams already building with modern SDKs -- rather than a credit-and-channel abstraction shared across SMS and WhatsApp.

Simple, fixed plans. MailKaka prices in flat monthly tiers by email volume and mailbox count. MSG91's credit-pack model works well across channels but adds a layer of unit conversion if all you send is email.

MSG91's email API and MailKaka's use different request formats, so this is a rewrite of the send call rather than a config change. The underlying pieces -- sender domain, recipient list, subject, HTML body -- map directly.

await fetch("https://www.mailkaka.in/api/emails", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${MAILKAKA_API_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    from: "hello@yourdomain.in",
    to: ["customer@example.com"],
    subject: "Welcome aboard",
    html: "<strong>It just works.</strong>",
  }),
});

Full API reference: docs.md migration prompt.