AgentMail: Product, team and how it was built
AgentMail (Email inbox API for AI agents, United States): 1 billion emails processed, October 2026. Evidence grade E: no revenue figure was checked. Team: 3 founders in 2025; Y Combinator lists a team of 10 (read November 2026), after a seed round in March 2026. Launched 8 July 2025; still running.Added 8 November 2026
- Outcome
- 1 billion emails processed, October 2026
- Evidence
- E no revenue figure was checked
- Launch
- 8 July 2025
- Status
- Still running
- Team
- 3 founders in 2025; Y Combinator lists a team of 10 (read November 2026), after a seed round in March 2026
- Outside funding
- Y Combinator (Summer 2025) and a seed round announced on 10 March 2026; US$6M according to a TechCrunch headline that Y Combinator lists
- Main channel
- Not stated
What is not verified
No revenue figure was found. I looked for a payment-processor profile, a founder interview with numbers and a funding article that this site may read; the seed amount of US$6M appears only as a TechCrunch headline that Y Combinator's page lists, and techcrunch.com is not read under this site's rules. The usage counts (1 billion emails, more than 10 million inboxes, more than 1 billion API requests in 30 days) are the company's own, and no outside party has checked them. A reader could look for a later interview with revenue or a count of paying customers. This story is grade E: the business is real and its product, price and customers are described from public pages, but no revenue figure was checked. Aiolum shows it as an idea worth studying, not as proof that it makes money.
AgentMail is an email API, a set of web addresses that a program calls to create mailboxes and to send and read mail, built for AI agents, programs that use a language model to carry out tasks on their own. One call creates an inbox with its own address. New mail reaches the agent by webhook, a message that the service sends to the customer's server the moment an event happens. The pricing page lists a free plan and paid plans from US$20 a month.
Haakam Aujla, Michael Kim and Adi Singh started it in 2025, "in the dorms" as the careers page says, and it joined Y Combinator's Summer 2025 batch. Their launch post of 8 July 2025 promised programmatic inboxes and usage-based pricing. The company announced a seed round on 10 March 2026, and Y Combinator's page lists a news headline that says it raised US$6M. On 21 October 2026 the company announced 1 billion emails processed; Y Combinator now lists a team of 10.
No revenue figure was found, so this is a grade E story: the headline is a usage count that the company states on its own pages. Paying customers are named in customer stories on its blog: Alchemy's AgentCard, which gives every agent an inbox by default, and Opendoor, which is moving its home-closing email onto AgentMail.
How much revenue does AgentMail make?
Each row shows the evidence grade and the source numbers from the list at the end of this page. The grades are explained in How Aiolum verifies.
| Fact | Value | Grade | How we know | Sources |
|---|---|---|---|---|
| Emails processed, October 2026 | 1 billion | C | Company statement. The press page lists "Launch: 1 billion emails" on 21 October 2026; the home page, read 8 November 2026, says "1B+ emails processed". | [5, 1] |
| Inboxes created, November 2026 | more than 10 million | C | Home page, read 8 November 2026: "10M+ inboxes". Agents create inboxes by program, so this is not a count of customers. | [1] |
| API requests in the 30 days before 8 November 2026 | more than 1 billion, with a peak of 100,000 a minute | C | Home page: "1B+ requests past 30 days, peaking at 100K requests/minute". | [1] |
| Emails processed, March 2025 | more than 5,000 | C | First saved copy of the site, 21 March 2025: "5000+ emails processed" and "Join the waitlist". | [11] |
| Founded | 2025, by 3 founders | C | Y Combinator page: year founded 2025; founders Haakam Aujla (CEO, before a quant researcher at Optiver), Michael Kim (CTO, before NVIDIA autonomous vehicles) and Adi Singh (before an investor at Accel, StepStone Group and Flex Capital). The careers page says the founders started the company "over a year ago in the dorms". | [3, 6] |
| Team, November 2026 | 10 people | C | Y Combinator page, read 8 November 2026 (team size 10). The careers page lists 9 open roles. | [3, 6] |
| Outside funding | Y Combinator Summer 2025; seed round announced 10 March 2026, US$6M as reported | D | The press page lists "Seed announcement" on 10 March 2026. The amount comes from a TechCrunch headline, "AgentMail raises $6M to build an email service for AI agents", that the Y Combinator page lists; the article itself was not read. | [5, 3] |
| Prices, November 2026 | Free; Developer US$20 a month; Startup US$200 a month; Enterprise custom | C | Pricing page, read 8 November 2026. Add-ons from US$2 a month. | [2] |
| Sending limits per day | 100 (Free), 1,000 (Developer), 15,000 (Startup) | C | Pricing page. Developer also caps 100 emails per 5 minutes and Startup 1,500. | [2] |
| Named customers | AgentCard by Alchemy (July 2026), Opendoor (September 2026) | C | Customer stories on AgentMail's blog with quotes from named staff of each customer. AgentCard reports about 70% more agent transactions after the integration, a customer's own result. | [7, 8] |
| Public launch | 8 July 2025 | C | Launch post on Y Combinator: "Usage-based pricing scaling with emails sent/received" and "No restrictive rate/sending limits". | [4] |
| Time from launch to 1 billion emails | 15 months | calc | Calculated: 8 July 2025 to 21 October 2026. | [4, 5] |
How to read this table: a grade C value is a statement by the company on a page it controls (its site, its blog or its Y Combinator page). A grade D value was reported by a third party that this page could not read. A "calc" value was computed on this page. No revenue figure exists, so no row is grade A or B.
| Plan | Per month, billed yearly (US$) | Per month, billed monthly (US$) | Limit |
|---|---|---|---|
| Free | 0 | 0 | 3 inboxes, 3,000 emails a month, 100 a day, 1 custom domain, "Sent via AgentMail" footer |
| Developer | 20 | 10 inboxes, 10,000 emails a month, 1,000 a day, 10 custom domains, 2 seats | |
| Startup | 200 | 150 inboxes, 15,000 emails a day, 150 custom domains, 10 seats, SOC 2 report | |
| Enterprise | custom | custom | up to unlimited inboxes, contract |
| Add-on: inbox, domain or 1,000 emails a month | 1.60 | 2 | each; US$19.20 a year on yearly plans |
| Add-on: seat | 4 | 5 | US$48 a year on yearly plans |
Plans include a number of inboxes, custom domains and emails. Add-ons are sold on the Developer and Startup plans: one more inbox, one more custom domain or 1,000 more emails a month for US$2 a month each (US$19.20 a year on yearly plans), and a seat for US$5 a month (US$48 a year). Enterprise adds usage-based pricing, white-label, an EU region, dedicated IPs and single sign-on.
When did AgentMail launch, and how did it grow?
From a waitlist page with 5,000 emails processed to 1 billion emails, in about 19 months. Each entry carries its grade.
- 21 March 2025CFirst saved copy of agentmail.to: a waitlist, "5000+ emails processed", and unlimited inboxes with usage-based pricing. [11]
- 8 July 2025CLaunch post on Y Combinator, Summer 2025 batch: the API-first email provider for AI agents. [4, 3]
- 10 March 2026DSeed round announced. Y Combinator lists a TechCrunch headline that gives US$6M. [5, 3]
- 16 July 2026CCustomer story: Alchemy's AgentCard gives every agent an AgentMail inbox by default. [7]
- 21 October 2026CThe company announces 1 billion emails processed. [5]
- November 2026CMore than 10 million inboxes by the company's count, a team of 10 on Y Combinator's page and 9 open roles. [1, 3, 6]
Why did AgentMail work?
Four causes, in the order they mattered. Each one is a reusable lesson.
One API call per inbox
An inbox is created with one call, with no OAuth login flow and no domain verification, and the free plan needs no credit card. A developer can test the product in minutes, and an agent can create its own inbox during a task.
Priced for programs, not people
Consumer mail is sold per seat. The launch post promised pricing that scales with emails sent and received; today's plans bundle many inboxes and sell more inboxes, domains and email volume as small add-ons.
Documentation that agents can read
The home page gives a prompt that tells an agent to read an onboarding guide and an llms.txt file, a plain-text index of the documentation for language models. The home page also links AgentMail plugins in the ChatGPT, Claude and xAI directories.
Named customers and launch videos
Customer stories name Alchemy and Opendoor with quotes from their staff. The press page lists launch videos with their view counts on X, for example 510,000 views for the AgentID launch, by the company's count.
How it was built
These details come from AgentMail's own pages. They are grade C. [10, 1, 2, 4]
- Runs on AWS in the United States and the European Union, with Vercel for web hosting, according to the subprocessor list updated 26 June 2026.
- Webhook events go through Svix, logins through Clerk, billing through Stripe, product analytics through PostHog and customer support through Plain (same list).
- SDKs for Python and TypeScript, a command-line tool, an MCP server (Model Context Protocol, a standard way for AI assistants to call outside tools), Skills and an SMTP relay.
- Email authentication records (DKIM, SPF and DMARC, which let receiving servers check that mail really comes from the domain), a suppression list of addresses not to mail, shared IPs, and dedicated IPs for Enterprise.
- AI features named in the launch post: semantic search across inboxes, automatic labels from user-written prompts, and structured data extraction from emails. No source names the model behind them.
- SOC 2 Type II compliance, according to the home page; the audit report comes with the Startup plan.
Who tried this before AgentMail, and why did they fail?
Four companies in our database of failed startups sold email or developer infrastructure and lost to a large platform. The values below are from that database and are not independently verified.
SendGrid Labs
The promisePlug-and-play communication tools for developers, from the email API company SendGrid.
Why it diedIt could not stand out from Twilio or from its own parent company.
Parse
The promiseA ready-made backend so that mobile developers could skip running servers.
Why it diedFacebook bought it and later shut it down while Google's Firebase grew.
Skiff
The promiseEncrypted email, documents and storage as a private alternative to Google Workspace.
Why it diedFree incumbents with large networks of users kept them; privacy alone did not move enough people.
Mailbox
The promiseA mobile email app that sorted mail with swipes and snooze.
Why it diedDropbox bought it and closed it; free email apps from Google and Apple took over its ideas.
The failed startups come from our database of 1,749 dead startups, retold here in our own words. Its entries are AI-assisted summaries of public sources, so these cards carry no evidence grade.
What changed
Each predecessor sold a mail or developer service and lost to a large platform that offered the same thing free or bundled: SendGrid Labs could not stand out from Twilio, Facebook shut Parse down after buying it, and Google and Apple kept the users that Mailbox and Skiff wanted. AgentMail faces the same giants, since Google, Microsoft and the big email APIs could add inboxes for agents.
The difference is the customer. The predecessors sold to people or app developers who already had email. AgentMail sells to programs that have no address at all and create inboxes by the thousand, a use that per-seat consumer plans and their terms were not made for. How long that gap stays open depends on how fast the large providers change their products.
Can one person copy AgentMail now?
The company, no. The method, yes.
Three founders built mail infrastructure that needs deliverability work, abuse handling and a security audit, then raised a seed round and hired. One person can copy the method on a smaller scale: find a service that assumes a human user and sell the version that a program can use through an API. Robotomail, another story on this site, is one founder doing that for agent email.
Where it is still open: Calendars, identity, phone numbers and payments for agents. AgentMail itself has added a calendar guide and an identity product (AgentID) in 2026, so the open space shrinks fast.
- 1List the services that an AI agent needs but that expect a human: email, phone numbers, payment cards, calendars, accounts.
- 2Ship an API and SDKs that create the resource in one call, with a free plan that needs no credit card.
- 3Publish documentation that an agent itself can read, such as an llms.txt file and an onboarding guide for agents.
- 4Write customer stories with named companies as soon as the first integrations go live.
What could go wrong for AgentMail?
The risks are the mirror image of the causes above.
What is not verified
No revenue figure was found. I looked for a payment-processor profile, a founder interview with numbers and a funding article that this site may read; the seed amount of US$6M appears only as a TechCrunch headline that Y Combinator's page lists, and techcrunch.com is not read under this site's rules. The usage counts (1 billion emails, more than 10 million inboxes, more than 1 billion API requests in 30 days) are the company's own, and no outside party has checked them. A reader could look for a later interview with revenue or a count of paying customers.
Sending limits and abuse risk
The launch post of 8 July 2025 promised "No restrictive rate/sending limits", and a service that creates inboxes by API could be used for bulk cold email. The pricing page read on 8 November 2026 lists daily caps (100, 1,000 and 15,000 emails on the three self-serve plans) and offers no inbox warming or rotation. The Terms of Service, updated 12 October 2026, forbid unsolicited email and require an opt-out link in commercial mail under the US CAN-SPAM Act. The use-cases page lists sales follow-up with leads among its uses.
Competition and model providers
Robotomail, another story on this site, sells mailboxes for agents as a one-person business, and general email APIs could add the same features. AgentMail does not resell a model, and its subprocessor list of 26 June 2026 names no model provider; its demand depends on agents built on models from OpenAI, Anthropic and others, and its home page links its plugins in the ChatGPT, Claude and xAI directories.
Team grew after funding
Three founders started the company in 2025. After the seed round of March 2026, Y Combinator lists 10 people and the careers page lists 9 open roles, so the team may soon pass 10.
Testimonials and logos
The home page quote from Clay is signed only "Alex, GTM Engineering", and a logo row names companies such as Replit, Factory and Polsia without further detail. Two customer stories (Alchemy's AgentCard and Opendoor) name the person quoted and were read for this page.
Sources
The grade next to each source is the best grade that the source can support. "Read in full" means that the text of the page was downloaded and the numbers were checked in it.
- C AgentMail home page, read 8 November 2026Read in full. Source for the usage counts, the customer quotes and logos, the SOC 2 claim and the plugin links.
- C AgentMail pricing page, read 8 November 2026Read in full. Source for the plans, add-ons and sending limits.
- C Y Combinator company page: AgentMail, read 8 November 2026Read in full, including the page data. Source for the founders, founding year, batch, team size and the TechCrunch headline in its news list.
- C Y Combinator Launch post, 8 July 2025: AgentMail, the API-first email provider for AI agentsRead in full. Source for the launch date, the reasons for the product and the early feature list.
- C AgentMail press page, read 8 November 2026Read in full. A dated list of launches and interviews; source for the seed announcement date and the 1 billion emails launch.
- C AgentMail careers page, read 8 November 2026Read in full. Source for the founders' note about starting in the dorms and the open roles.
- C AgentMail blog, 16 July 2026: How AgentCard by Alchemy gives every paying agent its own inboxRead in full. A customer story written by AgentMail with quotes from the customer.
- C AgentMail blog, 19 September 2026: How Opendoor is rebuilding its closing workflow on AgentMailRead in full. A customer story written by AgentMail with a quote from the customer.
- C AgentMail Terms of Service, updated 12 October 2026Read the sections on commercial email, prohibited uses and automated actions.
- C AgentMail subprocessors, updated 26 June 2026Read in full. Source for the hosting, webhook, login, billing, analytics and support services.
- C Internet Archive copy of agentmail.to, 21 March 2025Read in full. The earliest saved copy found through the Wayback availability API; source for the waitlist and the early email count.
- C AgentMail use cases page, read 8 November 2026Read in full. Source for the listed uses, including sales follow-up.
- C Database of failed startups, local exportLocal export. AI-written summaries, not independently verified. Source for the failed predecessors.
Run this company? Send corrections or a verified figure to aiolum@livyden.com