An email API built for sending into Japan ─ live now, ready to use today
Handemailover
to your AI.
Reading, writing and sending all end with a word to your AI.Sending and receiving, newsletters and scheduled delivery, open tracking and unsubscribe management. All of it is in one fixed monthly fee, with no overage billing. The hard part, DNS, we set up for you.
The first 100 free sign-ups get the right to half price for life on Standard and Business(Standard ¥1,480 → ¥740/month, incl. tax).
A Google login is all it takes; your API key is issued on the spot. The free plan (3,000 emails/month) needs no credit card and never expires. For the full specs, head to theservice site (harumail.app).
Send a thank-you email to Tanaka-san, who I met with yesterday. Show me the wording before it goes out.
Here is the draft.
Subject: Thank you for your time yesterday
Dear Tanaka-san, thank you for making time yesterday…
Draft approval ─ by design, the AI cannot send on its own.
Why
We built an email backbone for the AI era, tilted toward peace of mind.
Handing email to an AI raises worry before it raises convenience. So HaruMail is designed to fall on the side where accidents do not happen. It never sends on its own. The bill never balloons. The hard parts are ours to carry. Those three are the foundation.
Sending via AI runs on approval: draft → your check → send. Sending without you is impossible by design
Fixed monthly fee, no overage billing. Hit the cap and it simply stops (we notify you at 90% and 100%)
SPF, DKIM and DMARC — the hard part of email — are all configured on our side. You just paste in the API key
Features
Send. Receive. Broadcast. Everything you need is included.
Sending API (feels almost like Resend)
A sending API you can wire in from a single curl. cc/bcc, attachments, duplicate-send protection (Idempotency-Key) and custom headers. Migrating is mostly a matter of swapping the endpoint and the key.
Receiving by API, too (inbound)
Pull the mail that lands on your domain through the API. Hand the whole inbox to an AI and let it sort what needs a reply and draft the answers. Inbound included as standard is something the big overseas providers do not offer.
Newsletters and scheduled broadcasts
Broadcasts of up to 1,000 messages at a time. Name merge fields, scheduling, open rates and automatic one-click unsubscribe (RFC 8058). Management APIs for lists (Contacts/Audiences) and templates are there too.
AI-first (MCP built in)
Give Claude or ChatGPT the connection URL and your API key, and the AI can send, receive and broadcast. We publish AI-readable docs (llms.txt) as well. Nothing to install in your dev environment.
Scheduled sends and event webhooks
Schedule, change or cancel a one-off email. Event notifications for sends, opens, clicks and failures (HMAC-signed, with retries) let you build drip sequences of your own.
Unsubscribes and suppression management
Addresses that unsubscribe are dropped automatically (transactional mail is designed to keep flowing). Bounced addresses are managed through the API too. Let the system carry your legal compliance.
Pricing
Every plan includes tax and every feature. The only difference is volume and domain count.
Launch offer: the first 100 free sign-ups get Standard and Business athalf price for life(Standard ¥740/month, Business ¥1,340/month, incl. tax).
¥0/month
- 3,000 emails/month
- 2 domains
- Inbound, MCP and CLI included
- No credit card
- No expiry
¥1,480/month
- 10,000 emails/month
- 3 domains
- All features
- ¥740/month with the first-100 right
¥2,680/month
- 50,000 emails/month
- 5 domains
- Invoice billing available
- ¥1,340/month with the first-100 right
¥4,480/month
- 100,000 emails/month
- 10 domains
- Over 100,000: custom quote
On every plan: sending + receiving + webhooks + MCP + CLI + duplicate-send protection + DNS setup on our side. No overage billing (sending stops at the cap; we notify at 90%/100%). Extra domains are +¥500/month (incl. tax). No minimum term and no cancellation fee. The half-price-for-life right goes to the first 100 free sign-ups and is locked in the moment you register. It is applied automatically at checkout when you upgrade (through 2026-12-31).
Start
A Google login, and you are live today.
There is no sign-up form to fill in. Log in with Google and your API key is issued on the spot (30 seconds, no credit card). Hand that key to your AI and you can already send email.
The first 100 free sign-ups get the right to half price for life.
The right is locked in the moment you register and is applied automatically at checkout when you upgrade (through 2026-12-31).
Registration happens on the HaruMail service site (harumail.app). Please review thePrivacy PolicyandTerms(both in Japanese). You can also reach us by email: info@webharu.com
FAQ
Frequently asked questions.
What is HaruMail?
HaruMail is a Japanese-language email sending and receiving API operated by Webharu Inc. It ships with MCP built in, so AI agents such as Claude and ChatGPT can drive it directly, and one fixed monthly fee covers sending, receiving, newsletters, scheduled delivery, open tracking and unsubscribe management. We launched it in August 2026; on the free plan a Google login is all it takes, and your API key is issued on the spot.
How is it different from Resend?
Four things, mainly. ① Built for sending into Japan — the dashboard, docs, error messages and support are all in Japanese. ② The inbound (receiving) API is included as standard. ③ You can schedule a broadcast (Resend’s batch send has no scheduling — our own research as of 2026-08-06). ④ The monthly fee is fixed with no overage billing (once you hit the cap, sending simply stops). The API feels almost the same as Resend’s, so migrating is mostly a matter of swapping the endpoint and the key.
Will the AI send email on its own?
No. Sending through AI runs on draft approval — the AI writes a draft, you check it, then it goes out — so by design the AI cannot send on its own judgment. Automated sending straight from cron or the API (form auto-replies, for example) behaves exactly as you coded it.
What happens if I go over the message cap?
Sending simply stops. No extra charge is billed. A notification email reaches you when you hit 90% and 100% of the cap, so a sudden halt never catches you off guard. You can move up to a higher plan at any time.
Do I need to set up SPF, DKIM and DMARC?
No. We configure the DNS records that determine deliverability on your behalf (we take custody of your name servers). All you do is paste in the API key you receive, and you can start sending.
Is there a free plan?
Yes. The Free plan covers 3,000 emails a month and up to 2 domains at no cost, and no credit card is required. It never expires, so you can keep using it for development and testing.
Can individuals and freelancers use it?
Yes. Some email services are limited to registered companies, but HaruMail welcomes sole proprietors and freelancers. Payment by invoice is available on the Business plan and above.
Can I send newsletters and broadcasts?
Yes. A broadcast can go to up to 1,000 addresses at a time, with name merge fields, scheduling, open-rate tracking and automatic one-click unsubscribe (RFC 8058). Note that under Japan’s Anti-Spam Act, email containing advertising or promotion may only be sent to people who gave prior consent. HaruMail automatically stops sending to anyone who has unsubscribed, so you can leave that side to the system too.
Can I start right now?
Yes. Sign up free with a Google login and your API key is issued on the spot, so you can send today (30 seconds, no credit card). On paid plans the API key arrives by email the moment payment completes.
What are the terms of the early-bird half-price-for-life offer?
The first 100 accounts to sign up free (with a Google login) receive the right to half price for life on the Standard and Business plans (Standard ¥740/month, Business ¥1,340/month, incl. tax). The right is locked in the moment you register and is applied automatically at checkout when you upgrade. Please claim it by 2026-12-31.
Is there a minimum term or a cancellation fee?
No. Monthly billing can be canceled at any time, and nothing is charged after you cancel.
Who operates HaruMail?
Webharu Inc. (Miyagi, Japan, founded 2020) develops and operates it. We are the same company behind HaruCMS, a Japan-made headless CMS. Our founder, Masato Kurita, runs the service with his face and background public; see our company profile.