Comparison — Postfleet vs Gmail
Postfleet and Gmail solve different problems for an AI agent: Gmail gives the agent a person’s mailbox through OAuth scopes and an API, while Postfleet gives it a dedicated inbox with screening before the model reads anything. Pick Gmail when the agent must act inside an existing account. Pick Postfleet when it reads mail from strangers.
When the agent gets its own address and reads mail from people you do not control. You get sender-auth verdicts, sanitization, spam and virus gates, an injection scan that fails closed, typed JSON, and approval before send, without an OAuth verification or a Pub/Sub topic.
When the agent must work inside a mailbox a person already uses, or needs Calendar, Drive, and Docs under the same identity. Budget for OAuth verification of restricted scopes, watch renewal, and the screening layer you will write yourself.
Pricing model. The Gmail API has no usage fee; a consumer account is free, and a custom domain needs a paid Google Workspace seat. Push notifications run through Cloud Pub/Sub, which has its own free tier. Restricted scopes in production also need a third-party security assessment that Google does not price. Postfleet is priced per comprehended message, at $0 for 100 a month, $20 for 1,500, and $200 for 25,000 or more, with unmetered sanitization on every plan.
“DIY” means the capability can be assembled on the platform but is not enforced as a built-in service. “Not documented” means the public product documentation reviewed does not substantiate the capability; it does not mean the capability is impossible.
Swipe or scroll to compare →
| Capability | Postfleet | Gmail |
|---|---|---|
| Comprehension & security | ||
| Prompt-injection screening with fail-closed handling | Yes | No |
| Content sanitization with an audit report | Yes | No |
| JSON Schema extraction with confidence scores | Yes | No |
| Automatic message classification | Yes | DIY |
| Blocking wait for a matching email | Yes | No |
| PDF text included in message processing | No | Not documented |
| Inbound SPF / DKIM / DMARC verdicts surfaced | Yes | DIY |
| Layered spam gate with quarantine and recovery | Yes | Yes |
| Virus gate with fail-closed delivery | Yes | Yes |
| Async attachment byte scanning before download | No | Not documented |
| Sending controls & delivery reliability | ||
| Server-enforced human approval before send | Yes | DIY |
| Automatic webhook retries | Yes | DIY |
| Dead-letter queue with self-serve redrive | Yes | DIY |
| Inbox essentials | ||
| MCP server (hosted + local) | Yes | Yes |
| REST API | Yes | Yes |
| Webhooks | Yes | DIY |
| Send + receive | Yes | Yes |
| Custom domains (DKIM / SPF / DMARC) | Yes | Yes |
| Threading | Yes | Yes |
| Mailbox-scoped API keys with read / send flags | Yes | Yes |
| Send allowlists / blocklists | Yes | DIY |
| Idempotent message sends | Yes | No |
| Where Gmail is broader today | ||
| The mailbox a person already uses, with its history and contacts | No | Yes |
| Calendar, Drive, Docs, and Chat under the same OAuth identity | No | Yes |
| Free consumer accounts; no usage fee on the Gmail API | No | Yes |
| Gmail search operators and unlimited labels | No | Yes |
| Mailbox storage measured in gigabytes | No | Yes |
Yes. An app requests OAuth scopes such as gmail.readonly, gmail.modify, and gmail.send, then reads and sends through the Gmail REST API or an MCP server that wraps it. Gmail has no agent mode; the agent uses the same API a mail client does, with the same consent screen, quota units, and daily sending limits.
Google runs hosted Workspace MCP servers, including one for Gmail, in Developer Preview as of September 2026. The documented Gmail tool surface covers reading, search, drafts, and labels. The most-used community server was archived in March 2026 and an actively maintained fork took its place, so expect this list to keep moving.
No. Google’s MCP documentation warns that connecting an agent to untrusted content carries indirect prompt-injection risk and advises reviewing AI-initiated actions, but no screening, sanitization, or blocking is documented. Postfleet sanitizes every inbound message, scans it for injection, and skips extraction when the scan flags risk.
Through users.watch, which publishes change notifications to a Cloud Pub/Sub topic. The watch must be renewed about every seven days or notifications stop silently, and Google states that notifications may be delayed or dropped, so most agents also poll history.list. Postfleet delivers webhooks with retries and a dead-letter queue, or blocks until a matching message arrives.
Restricted scopes such as gmail.readonly and gmail.modify need Google’s OAuth verification, and past 100 test users a third-party security assessment that is renewed annually. Google does not publish the assessment price; assessors quote their own fees. A hosted agent inbox absorbs that step once, for every customer.
The same table and the same legend, against the other ways teams give an agent an inbox.
Last verified September 6, 2026. We compared documented product behavior, not what could be built with additional infrastructure. Gmail links point to its primary documentation; Postfleet links point to the product pages that describe the corresponding controls.