AgentMail review (2026): pricing, inbox API for AI agents, verdict

What AgentMail is

AgentMail is an email inbox API for AI agents. Where a transactional service gives a program a send endpoint, AgentMail gives an agent an inbox of its own: a persistent address, provisioned in one API call, that can send and receive, keep threads, hold attachments and drafts, schedule sends and raise a signed webhook whenever something arrives. The company, AgentMail, Inc., describes itself as the first email provider built for agents, cites a $6 million seed round on its site, and sells the product to developers building support agents, browser agents and multi-tenant agent platforms. It belongs in this directory because people searching for inboxes find it, not because it suits cold email, which its terms rule out.

AgentMail pricing

Four plans priced by inboxes, with a calculator for extras. Free gives 3 inboxes, 3,000 emails a month, 100 a day, 3 GB of storage and two team members with Discord support, and needs no card. Developer is $20 a month for 10 inboxes, 10,000 emails a month, 1,000 a day and 100 every five minutes, 10 GB, 10 custom domains, two seats and email support. Startup is $200 a month for 150 inboxes, 150 custom domains, 10 seats, 15,000 emails a day, a SOC 2 report and a shared Slack channel; its monthly email total is not listed on the plan table. Enterprise is quoted, with unlimited inboxes, dedicated IPs, a white-label platform, EU region or bring-your-own cloud, usage-based pricing, an SLA and SSO. Beyond a plan’s allowance, inboxes and domains cost $2 a month each and emails $2 per 1,000, and yearly billing is 20% off.

The terms are short. Subscriptions renew automatically unless cancelled before the end of the cycle, from the dashboard or through support, fee changes take effect at the next cycle, and all fees are non-refundable except where the law requires. A trial, where offered, charges the card on its last day unless cancelled.

API, deliverability and integrations

Everything is done through the API or the SDKs: create an inbox, send, read threads, label, attach, draft and schedule, with inbox pods for grouping, webhook endpoints and websockets for inbound events, metrics, and an SMTP relay for software that only speaks SMTP. An MCP server lets an agent framework drive it directly. On the deliverability side AgentMail configures DKIM, SPF and DMARC for its own agentmail.to addresses, hands you the records for custom domains, keeps a suppression list, removes the AgentMail footer on paid plans, sends from optimised shared IPs and offers dedicated IPs on Enterprise. Its own guidance is that authentication, sender reputation and content decide placement, which is true of every provider.

Cold email fit

None, by design. The acceptable-use list in the terms includes spam, phishing and unsolicited messaging, the daily caps of 100, 1,000 and 15,000 emails are sized for agents holding conversations rather than campaigns, there is no warm-up, and shared IPs carry every customer’s reputation together. An agent that replies to inbound leads, confirms meetings or fetches verification codes is the intended job. Cold outreach belongs on dedicated Google Workspace or Microsoft 365 inboxes behind a sequencer.

Who AgentMail is for, and who should look elsewhere

AgentMail suits developers giving AI agents their own email identities for support, scheduling, verification codes and two-way conversations, from a hobby project to a multi-tenant product. It is a poor fit for cold email of any kind, or for anyone who needs refunds or warm-up for high-volume outbound.

AgentMail alternatives

SendGrid and Mailtrap are the transactional senders for software that only needs to send, both with terms that bar unsolicited mail. The email platforms and registrars category lists the hosting-side tools. Unipile is the other API-first product here; it connects existing LinkedIn and email accounts rather than creating inboxes.

AgentMail and PureMail

They do not overlap. AgentMail gives an agent an inbox to converse from; PureMail inboxes are Google Workspace and Microsoft 365 accounts on secondary domains for cold outreach through a sequencer. A team running both would keep the agent’s conversational mail on AgentMail and its prospecting on dedicated inboxes, so neither reputation touches the other.