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The email backend for your SaaS

Building a product that has to email your own users - verification codes, receipts, notifications - and maybe read their replies too? Mektup is the managed email infrastructure underneath: one API and one account across every domain you (or your clients) own, sending and receiving. It's also multi-tenant, so you can provision a real, isolated inbox for each of your own customers. Ship email in your product without stitching together a sending API and a separate inbox service.

Send transactional email for your users

The same way teams reach for a transactional email API today, your backend calls Mektup to send your product's mail - sign-up confirmations, password resets, receipts, alerts - from your own domain, properly authenticated with DKIM, SPF, and DMARC.

// your app emails one of your users
await fetch("https://api.usemektup.com/v1/emails", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.MEKTUP_API_KEY}`,
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    from: "receipts@yourproduct.com",
    to: user.email,
    subject: "Your receipt",
    html: renderReceipt(order),
  }),
});

An inbox for every customer, not just outbound

Because Mektup is multi-tenant email infrastructure, your product isn't limited to sending. You can provision a real, isolated mailbox for each of your own customers - acme@yourapp.com, globex@yourapp.com - through the same API, while your app and its AI agents keep scoped access and each customer sees only their own mail. That turns "email inside our app" into a first-class feature instead of a send-only side channel.

...and receive their replies

Unlike a send-only API, the address you send from is a real inbox. When a user replies to a receipt or a notification, it doesn't bounce - it lands in a mailbox your team (or an automated workflow) can read over the API, IMAP, or the webmail dashboard. That turns "no-reply" into a real support and conversation channel with no extra service.

One account, every domain

Add as many domains as your product or your clients own, and run them all from a single account and API key - no separate signup per domain. Each domain gets its own DKIM keypair and authentication automatically. Pro adds team members (5 included), and for agencies, scoped client logins - where each client sees only the specific mailboxes or domains you grant - are on Enterprise.

Managed, not self-hosted

Mektup runs and operates all the mail infrastructure - real MX, IMAP, SMTP, and DKIM signing on its own outbound servers. There is nothing for you to host, scale, patch, or keep online. You integrate an API; Mektup keeps the mail flowing. Delivery status (sent / deferred / bounced) comes straight from the receiving server's real SMTP response, so your product gets true delivery visibility, not a tracking-pixel guess.

For your team and your AI agents

Everything is a documented REST endpoint and a native MCP tool, so you can build email into your product in code, and an AI agent (yours or your users') can provision domains, send, and act on incoming mail on its own. See the AI agents guide for that side.

What it costs

Start free (1 domain, 3,000 emails/month), scale on Starter and Pro (up to 25 domains, 150,000 emails/month, team seats), and for platforms and agencies that need unlimited domains and scoped client logins, talk to us about Enterprise.

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FAQ

Common questions

Can I use Mektup to send transactional email to my own product's users?

Yes. Point your backend at the REST API and send verification codes, receipts, and notifications to your users from your own domain - the same way teams use a transactional email API today. And because Mektup receives too, replies land in a real inbox instead of disappearing.

Can I manage many domains or client accounts from one place?

Yes. One account and API key work across every domain you add, so an agency or platform runs mail for many client domains without a separate account each. Pro adds team members; scoped client logins for agencies, where each client sees only the mailboxes or domains you grant, are on Enterprise.

Do I have to host or run any mail servers?

No. Mektup is fully managed and operates all the infrastructure (real MX, IMAP, SMTP, DKIM). You add DNS records per domain once and use the API - nothing to install, scale, or keep online.

Ready when you are

Managed email infrastructure for your product

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