Your agent gets its own email address.

ACK gives AI agents real inboxes. They receive mail, reply in the same thread and draft messages for you to approve, all through a REST API or MCP.

Start a trial

14-day trial. Cancel any time.

From: Dana Ruiz <dana@northwind.co>
To: support-agent@trial.ack.now
Subject: Invoice 4471 charged twice

Hi, I see two charges for invoice 4471 on my card this morning. Can you refund one?

From: support-agent@trial.ack.now
To: dana@northwind.co
Subject: Re: Invoice 4471 charged twice

Found the duplicate and refunded it. You'll see it in 3–5 days.

ACKReplied in thread · 09:14 · 41 seconds after it arrivedReplied in thread · 41s

A full mailbox, not a send-only pipe.

Your agent can hold a conversation the way a person on your team would.

See what agents can do →

Receive and read mail

Every inbox gets a real address. Messages arrive with their attachments and are grouped into threads.

Reply in the same thread

Replies keep the conversation together in the customer's mail app, so nobody gets a stray new email.

Draft for a person to approve

Let the agent write the reply and hold it as a draft until someone on your team sends it.

Hear about new mail instantly

Signed webhooks tell your system when mail arrives, sends, bounces or gets opened.

Send from your own domain

Add your domain and ACK sets up the records that keep your mail out of spam folders.

Keep each agent in its lane

Keys can be limited to one inbox, so an agent only sees the mail it's meant to handle.

Bring your old mail

Import an mbox, a zip of .eml files or pull from an IMAP server. ACK threads it like live mail.

One request makes an inbox.

Call the REST API from your code, or point any agent that speaks MCP at ACK and it can use email straight away.

Call the REST API from your code, or point any MCP-capable agent at ACK.

Developer quickstart →

REST API

curl https://api.ack.now/v0/inboxes \
  -H "Authorization: Bearer ack_live_…" \
  --json '{"username": "support-agent"}'

# {"inbox_id": "support-agent@trial.ack.now", …}

curl https://api.ack.now/v0/inboxes \
  -H "Authorization: Bearer ack_…" \
  --json '{"username": "support-agent"}'

MCP server

{
  "mcpServers": {
    "ack": {
      "url": "https://mcp.ack.now/mcp",
      "headers": { "x-api-key": "ack_live_…" }
    }
  }
}

"ack": {
  "url": "https://mcp.ack.now/mcp",
  "headers": {
    "x-api-key": "ack_live_…"
  }
}

Safe to hand to an agent.

Encrypted in transit

Mail travels over TLS between servers. Secrets are encrypted at rest, and webhooks only go to https.

Mail isn't orders

ACK tells your agent that mail comes from outside senders, so it can treat instructions in an email as content, not commands.

Your sender reputation, protected

Bounces and complaints are watched for every organisation. Accounts that cross the line are paused for a person to review.

Priced per organisation. No meter running.

One plan, every feature

$19per organisation, per month

Inboxes included: 10
Each extra inbox: $2 a month
REST API, MCP server, webhooksAPI, MCP, webhooks: Included
Your own domains: Included

Start a trial Prices in USD. Cancel any time from the billing page.

14-day trial

A card is needed to start, and you aren't charged until the trial ends. The trial includes 100 outbound emails. Receiving is unlimited.

Fair use, never overage

Each inbox can send 1,000 emails a month at full speed. Past that, sending slows down until the next month. You're never charged for more.

A gentle start for new senders

New organisations send up to 200 emails a day in week one and 1,000 a day in week two, which keeps your domain's reputation healthy.

Full pricing and FAQ →

Give your agent an inbox today.

Sign up, create an inbox and send your first email in a few minutes.

Start a trial