The complete
email platform

Transactional API, marketing broadcasts, our own mail servers and the deliverability tooling around them. One platform from the first API call to the inbox.

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1,000 emails / month free · No credit card required

Most teams stitch these together from four vendors.
KubeMail runs all of them for you.

Email API

Broadcasts

Own MTA fleet

Dedicated IPs

Deliverability

Webhooks

Analytics

iOS app

Not just an API. The whole platform.

An email API is the first five percent. KubeMail also gives you the dashboard, the mail servers, the analytics and the deliverability work that decide whether a message actually lands.

New emailSend test to meSend

From: Acme <news@acme.com>
To: ada@example.comgrace@example.com
Subject: What's new in October

Sender name
Plain-text part
Unsubscribe link

Compose, test and send

Write HTML or plain text, preview it, send a test to yourself and get deliverability hints before anything leaves. Broadcasts to 100,000 recipients run through the same pipeline.

acme.comVerified

TXTkm1._domainkeyDKIM

CNAMEbouncesReturn-path

TXT_dmarcDMARC

CNAMEtrackTracking

Domains verified in minutes

DKIM keys generated per domain, copy-paste DNS records and live verification, with SPF alignment through a custom return-path.

Delivered

99.2%

Opened

41.8%

Clicked

9.6%

Bounced

0.4%

Logs and analytics

Every message and event, searchable and charted in real time — delivered, bounced, opened and clicked, per domain and per mailbox provider.

old@yahoo.comHard bounce

no-thanks@gmail.comUnsubscribed

angry@outlook.comComplaint

typo@gmial.comHard bounce

List-Unsubscribe-Post: List-Unsubscribe=One-Click

Suppressions and compliance

Hard bounces, complaints and unsubscribes are suppressed automatically. Broadcasts get one-click List-Unsubscribe headers automatically.

Overview

36,120of 50,000

Delivered35,830

Opened15,101

Bounced144

Native iOS app

Delivery health, logs, domains and API keys in your pocket. Spot a bounce spike before your customers do.

Send your first email in minutes

One predictable REST API for single sends, batches of 1,000 and broadcasts to 100,000 recipients. No SDK required — if it can make an HTTPS request, it can send through KubeMail.

curl -X POST https://api.kubemail.app/v1/emails \
  -H "Authorization: Bearer km_live_xxxxxxxxxxxx" \
  -H "Content-Type: application/json" \
  -d '{
    "from": "Acme <hello@acme.com>",
    "to": "ada@example.com",
    "subject": "Your login code: 482913",
    "html": "<p>Your code is <strong>482913</strong></p>"
  }'

202 Accepted{ "id": "msg_2Hc9xTq4Lk", "status": "queued" }

Queuedada@example.comIdempotency-Key

HTTP 202 { "id": "msg_2Hc9xTq4Lk", "status": "queued" }

HTTP 202 { "id": "msg_7Rv1pWm0Qa", "status": "queued" }

HTTP 202 { "id": "msg_4Nd8sYz2Hc", "status": "queued" }

HTTP 202 { "id": "msg_9Kt3bEx6Uo", "status": "queued" }

HTTP 202 { "id": "msg_1Fq5cJw7Ri", "status": "queued" }

Retries that never double-send

Pass an Idempotency-Key and any retry within 24 hours returns the original response. Network blips and queue hiccups stop being a support ticket.

Delivered14:02:31
ada@gmail.com250 2.0.0 OK
Opened14:03:12
ada@gmail.comiPhone · Mail
Bounced14:03:40
old@yahoo.com550 5.1.1 user unknown
Deferred14:04:05
team@outlook.com421 rate limited, retrying

Signed, real-time webhooks

Every delivery, deferral, bounce, complaint, open and click is pushed to your endpoint the moment it happens, HMAC-signed so you can trust it.

Built to land in the inbox

Deliverability isn't a feature you bolt on. It comes from owning every hop between your API call and the recipient's mailbox.

Our own mail servers

Delivery runs on a KumoMTA fleet we operate ourselves — a Rust MTA built for millions of messages per hour, not a reseller relay.

Per-ISP traffic shaping

Connection limits, rates and backoff tuned per mailbox provider, so Gmail, Outlook and Yahoo each get exactly the pace they accept.

Dedicated, warmed IPs

Enterprise senders get their own IP addresses with clean reverse DNS, warmed gradually so your reputation is yours alone.

Aligned authentication

SPF, DKIM and DMARC align out of the box through a custom return-path — no edits to your root SPF record.

Blocklist and IP health

Sending IPs are checked continuously against major blocklists and scored on bounce and complaint rates.

Best practices by default

A plain-text part is generated for HTML-only mail and bounces, complaints and unsubscribes are suppressed automatically.

Under the hood

Edge API
Auth, validation and rate limits on 300+ edge locations
Durable queues
Your request returns in milliseconds; spikes are absorbed
KumoMTA
DKIM signing, ISP shaping, bounce classification
Inbox
Events stream back to logs, stats and webhooks

From the API call to the inbox, every hop runs on infrastructure we operate — so when something needs fixing, there's exactly one team to fix it.

edge locations accept your API calls: 300+; edge locations accept your API calls
emails per batch request: 1,000; emails per batch request
recipients per broadcast: 100k; recipients per broadcast
idempotency replay window: 24h; idempotency replay window

Simple, predictable pricing

Pay per mailbox, monthly or yearly. Add or remove mailboxes anytime.

Mailboxes

Basic

Professional email on your own domain.

$1.99$2.49/mailbox/mo

5 mailboxes · $119.40 billed yearly · save $30.00

10 GB storage per mailbox
300 emails / day per mailbox
Unlimited domains & aliases
Webmail & iOS app
Spam & virus protection
Email support

Start with Basic

Pro

Enterprise

For organizations that need isolation and scale.

$5.59$6.99/mailbox/mo

5 mailboxes · $335.40 billed yearly · save $84.00

100 GB storage per mailbox
10,000 emails / day per mailbox
Everything in Pro
Dedicated IP addresses
API & webhooks
Priority support & SLA

Go Enterprise

Just trying it out? The free tier includes 1,000 emails / month, no credit card required. Start for free

Questions, answered

Can't find what you need? Visit support.

How is KubeMail different from an email API?

An API only accepts your message. KubeMail also runs everything after that: the mail servers that deliver it, per-ISP traffic shaping, dedicated IPs, suppression handling, logs and analytics, a web dashboard with Compose, and a native iOS app — one platform and one bill.

How fast can I start sending?

Create an account, add your domain, paste four DNS records, and create an API key. Most teams send their first email in under five minutes — DNS propagation is usually the slowest part.

What makes KubeMail fast at scale?

The API runs on Cloudflare's edge and only queues your message, so requests return in milliseconds. Delivery is handled by KumoMTA, a Rust MTA running on bare metal with per-ISP connection and rate shaping.

Do I need to change my existing SPF record?

No. KubeMail uses a custom return-path (bounces.yourdomain.com) as a CNAME, which gives you SPF alignment without touching your root SPF record. You'll also publish a DKIM key and, ideally, a DMARC record.

What happens when I exceed my monthly quota?

Paid plans bill usage beyond the included volume as overage — $0.0008 per email on Pro. The Free plan includes 1,000 emails per month; you can upgrade at any time from the Billing page in your dashboard.

How do you handle bounces and complaints?

Hard bounces and spam complaints are added to your suppression list automatically and future sends to those addresses are dropped. Every event is also delivered to your webhooks and visible in the logs with a plain-English explanation of the SMTP code.

Can I get a dedicated IP?

Yes — Enterprise includes a dedicated IP, warmed gradually and monitored against major blocklists (Spamhaus, Barracuda, SpamCop, SORBS).

Email, handled end to end

1,000 free emails every month. Upgrade to millions when you need them.

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The completeemail platform