SuperMailOS
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Comparison · facts checked 16 Oct 2026

SuperMailOS vs AgentMail

Inboxes for agents, or your team's email with agents in it.AgentMail is, in its own words, “an email provider built for AI agents”: inboxes created over an API, for developers and the products they build. SuperMailOS is business email for your team, and every seat includes inboxes for your AI agents, with a person who approves what they send to someone new. Both give an agent a real inbox. They’re built for different buyers.

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The short answer

Choose AgentMail ifYou're building a product that creates inboxes for many agents or users, and you want an API-first service with SDKs and a free start.
Choose SuperMailOS ifYour team needs its own email, and you want AI agents working beside it on your domain, with a person approving what they send to someone new.

Last updated . AgentMail details from public sources, 16 Oct 2026. Where they win comes first.

01 Side by side

AgentMail and SuperMailOS, row by row.

An honest, current comparison. Where we're unsure of a competitor detail, we describe what SuperMailOS does rather than assert theirs.

Feature and price comparison: AgentMail versus SuperMailOS.
FeatureAgentMailSuperMailOS
Built forAgentMailIn its own words, “an email provider built for AI agents”SuperMailOSYour team's business email, with inboxes for its AI agents in every seat
PriceAgentMailFree (3 inboxes) · Developer $20/mo for 10 · Startup $200/mo for 150 · extra inboxes $2/moSuperMailOSPro $4/mo per mailbox ($3 annual) · Business $6/mo ($5 annual). Agent inboxes included: 2 per seat on Pro, 5 on Business
25 agent inboxesAgentMail$50 a month (Developer plus 15 extra inboxes)SuperMailOSYes$30 a month: 5 Business seats, which also give 5 people their own mailboxes
Your team's emailAgentMail2 team members on Developer, 10 on Startup; extra seats $5/moSuperMailOSYesA mailbox for every person, with webmail, IMAP/SMTP and free aliases
Your own domainAgentMailOn paid plans (10 on Developer); not on FreeSuperMailOSYesOn every plan: up to 3 domains on Pro, unlimited on Business
Approval before sendingAgentMailBuilt from drafts and key permissions: “A draft is only an approval step if the agent cannot send on its own.”SuperMailOSYesOn by default: email to someone new waits for a person, and the agent’s key can’t approve it or change its rules
Email sent to trick an agentAgentMailAgent Armor scans incoming mail (AgentMail Labs, US only); it starts in a monitor mode that never holds mail, with a hold mode to opt intoSuperMailOSYesOur own sender check on every email to an agent: spoofed or blocked mail is held until a person releases it, and hidden text is removed before it reads
Says it's an AIAgentMailFree-plan mail carries a “Sent via AgentMail” footerSuperMailOSYesEvery email ends with a line naming the agent and the person it works for
Developer toolsAgentMailYesREST API (v0), Python and Node SDKs, webhooks, WebSockets, an MCP server, and guides for many agent frameworksSuperMailOSREST API with an OpenAPI spec and samples, signed webhooks and an MCP server. No SDKs yet
Inboxes for your own usersAgentMailYesPods for multi-tenant products; unlimited inboxes on EnterpriseSuperMailOSNoNot yet: agent inboxes are for your own team’s agents
Included With caveats Not includedAgentMail details compiled from public sources as of 16 Oct 2026 and may have changed since. SuperMailOS details reflect current plans.

AgentMail facts from AgentMail’s own pages: AgentMail pricing, AgentMail: what it is, AgentMail: human-in-the-loop, AgentMail: Agent Armor, AgentMail: API reference, AgentMail: docs index · checked 16 Oct 2026

02 Honestly

Where AgentMail is the better choice.

If any of these describe you, AgentMail is probably the right call — and that's fine.

01

A free start

A free plan with 3 inboxes, no card and no domain to set up.

02

Built for products

Pods for multi-tenant products, Enterprise plans with unlimited inboxes, and WebSockets for live events.

03

A wide developer ecosystem

Python and Node SDKs, and guides for LangChain, the OpenAI Agents SDK, the Claude Agent SDK, Vercel and more.

04

Compliance paperwork

A SOC 2 report from the Startup plan, and an EU region on Enterprise.

And where SuperMailOS is

01

Your team's email included

Every person gets a real mailbox, with webmail and IMAP, and every seat includes agent inboxes. One workspace, one bill.

02

A person in the loop by default

Email to someone new waits for approval, and the agent's own key can't approve it or loosen its rules.

03

Spoofed mail never reaches the agent

We check who really sent each email to an agent and hold what fails. Hidden text is removed before it reads.

04

Priced for teams

25 agent inboxes come with 5 Business seats for $30 a month, along with 5 people's mailboxes.

Which one fits you

Building a product that hands out inboxes by the hundred, or after a free agent inbox today: AgentMail. A team that wants its own email with AI agents working beside it, and a person approving what they send to someone new: SuperMailOS.

SuperMailOS is hosted business email: we run the mail servers and the deliverability work, and agent inboxes are part of it, on your own domains.

Still comparing? Ask your AI — we've written the question.

ChatGPT ↗Claude ↗Perplexity ↗Grok ↗Google AI Mode ↗

03 Getting started

An agent at work in three steps.

Nothing new to wire up for your team: the agent's inbox lives in your workspace, beside everyone else's.

01

Create the agent inbox

In Settings → Agents or with one API call: a name, an address on your domain, and the person it works for.

02

Give it its key

The key reaches that one inbox. Use it from your code, or from any MCP client that can send an API key.

03

Choose how freely it sends

Ask for new people (the default), ask every time, or send within daily limits.

04 Questions

Questions people ask.

Something else? Write to us — a real person answers, usually the same day.

Talk to us
Is SuperMailOS an AgentMail alternative?+
For a team that wants agents working beside its people, yes: agent inboxes come with SuperMailOS seats, on your own domain, with approval for new recipients and held spoofs on by default. For a product that creates inboxes for its own users, AgentMail is built for that and SuperMailOS isn't yet.
How much does AgentMail cost?+
Free has 3 inboxes and a “Sent via AgentMail” footer; Developer is $20 a month for 10 inboxes; Startup is $200 a month for 150; extra inboxes are $2 a month each; Enterprise is priced by contract. From AgentMail's pricing page, checked 16 Oct 2026.
How much do agent inboxes cost on SuperMailOS?+
They're included with seats: 2 per seat on Pro ($4 a person a month) and 5 on Business ($6), and the 14-day trial includes 3. 25 agent inboxes come with 5 Business seats, $30 a month, along with 5 people's mailboxes.
Can an AgentMail agent wait for my approval?+
AgentMail's guide builds approval from drafts and key permissions: “A draft is only an approval step if the agent cannot send on its own.” On SuperMailOS, approval for new recipients is on by default and belongs to the inbox's rules, so the agent's own key can't skip it.
What protects an agent from tricky email on each?+
AgentMail's Agent Armor scans incoming mail for attempts to manipulate an agent. It's in AgentMail Labs, in the US only, and starts in a monitor mode that never holds mail; a hold mode is optional. SuperMailOS checks who really sent every email to an agent, holds what fails until a person releases it, and removes hidden text before the agent reads. No filter catches every trick, so give agents narrow instructions either way.
Can my agents use my own domain?+
On AgentMail's paid plans, yes (10 domains on Developer, none on Free). On SuperMailOS, agents always use a domain you've verified, on every plan, the same as your team.

Give your first
agent an inbox.

14 days free with 3 agent inboxes. No card, and your domain stays yours.

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