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Cooper Email is an email API that gives each AI agent its own inbox. Free is $0 and includes 5 inboxes and 5,000 emails a month.

Retrieved 2026-09-27

Cooper Email vs the Gmail API

The Gmail API reads and sends mail for an existing Google account. It does not create a new inbox for an agent.

Google’s quota page (last updated 2026-09-10 UTC) says standard use has no additional cost, and that charges for usage above a daily threshold are planned later in 2026.

Sources: Gmail API usage limits

Gmail APICooper Email
InboxAn existing Gmail or Google Workspace mailbox, authorized with OAuthPOST /api/v1/onboard creates username@cooperemail.com and an API key
PriceNo additional cost for standard use. Daily billing threshold is 80,000,000 quota units per project per day before charges are planned.$0 · 5 inboxes · 5,000 emails/month · 1 custom domain
Send quotamessages.send costs 100 quota units. Per-user per-project limit is 6,000 units per minute. Per-project limit is 1,200,000 units per minute.Plan caps: Free 5,000/month, Starter 25,000/month, Pro 250,000/month. No separate per-minute cap in Cooper’s API.
IsolationThe human’s mailbox, unless you provision a separate Google userOne inbox per agent on the Cooper account
SearchGmail search syntax on that mailboxAccount-wide full-text search across Cooper inboxes
  • Google Workspace user licenses are separate from the API page and are not quoted here.
  • A 500-recipient cap per message is stated on the same quota page.

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