HTML version: https://cooperemail.com/compare/gmail-api

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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](/pricing).

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](https://developers.google.com/workspace/gmail/api/reference/quota)

|  | [Gmail API](https://developers.google.com/workspace/gmail/api/reference/quota) | [Cooper Email](/pricing) |
| --- | --- | --- |
| Inbox | [An existing Gmail or Google Workspace mailbox, authorized with OAuth](https://developers.google.com/workspace/gmail/api/reference/quota) | [POST /api/v1/onboard creates username@cooperemail.com and an API key](/pricing) |
| Price | [No additional cost for standard use. Daily billing threshold is 80,000,000 quota units per project per day before charges are planned.](https://developers.google.com/workspace/gmail/api/reference/quota) | [$0 · 5 inboxes · 5,000 emails/month · 1 custom domain](/pricing) |
| Send quota | [messages.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.](https://developers.google.com/workspace/gmail/api/reference/quota) | [Plan caps: Free 5,000/month, Starter 25,000/month, Pro 250,000/month. No separate per-minute cap in Cooper’s API.](/pricing) |
| Isolation | [The human’s mailbox, unless you provision a separate Google user](https://developers.google.com/workspace/gmail/api/reference/quota) | [One inbox per agent on the Cooper account](/pricing) |
| Search | [Gmail search syntax on that mailbox](https://developers.google.com/workspace/gmail/api/reference/quota) | [Account-wide full-text search across Cooper inboxes](/pricing) |

- 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.

[All comparisons](/compare) · [Pricing](/pricing) · [AgentMail alternatives](/alternatives/agentmail) · [FAQ](/faq)