Alternatives guide
Best AgentMail Alternatives (2026)
AgentMail gives each agent an inbox through one API call, with threads, search, webhooks, WebSockets, an MCP server, IMAP and SMTP, custom domains, inbox pods and a calendar on every inbox. Its Free plan has 3 inboxes and 3,000 emails a month (100 a day) with an AgentMail footer on sent mail. Developer is $20 a month for 10 inboxes, and Startup is $200 a month for 150 inboxes and a SOC 2 report. Teams look elsewhere for a verification-code field, a lower first paid price, an inbox on a domain they already send from, EU hosting or a setup they run themselves.
Sources: AgentMail pricing, AgentMail docs index
The options at a glance
| Option | Free tier | Paid |
|---|---|---|
| Lumbox | 3 inboxes, 500 emails received and 100 sent a month, with OTP extraction and MCP access. | Starter $9/mo (10 inboxes, 5,000 received and 2,000 sent a month), Pro $29/mo, Scale $99/mo. |
| Resend Inboxes | 3 inboxes and 3,000 emails a month (100 a day), shared with all your sending. | Pro from $20/mo (50,000 emails), with extra inboxes at $1/mo each on paid plans. |
| Nylas Agent Accounts | 3 Agent Accounts, 3,000 agent emails a month and 3 GB of storage. | Essentials $15/mo (10 Agent Accounts, 10,000 emails, 1 custom sending domain), Pro from $49/mo (50 Agent Accounts). |
| OpenMail | 3 inboxes and 3,000 emails a month (100 a day), with 3 GB of storage. | Pro €9/mo plus usage (10 inboxes, then €1 an inbox; 10,000 emails, then €0.001 an email). |
| Robotomail | 1 mailbox with 10 sends and 10 receives a month, only with your own verified address. | Solo $5/mo (1 mailbox, 500 sends and 500 receives), Starter $19/mo (10 mailboxes), Growth $79/mo, Scale $199/mo. |
| Cloudflare Agentic Inbox | Unlimited inbound routing on Workers Free. Sending to anyone other than your verified addresses needs Workers Paid. | Workers Paid from $5/mo per account, with 3,000 emails a month included, then $0.35 per 1,000. |
Each alternative in detail
1Lumbox
An agent inbox API built around the login step: inboxes the agent owns, OTPs, magic links and backup codes extracted to JSON, long-poll /otp and /wait endpoints, an AES-256-GCM credential vault, IMAP and 104 MCP tools. An agent can start its own signup with POST /v1/orgs, and its key works once a human approves the signup in a browser.
- Who it fits:
- Agents that sign up for services, wait for a verification code and log in on their own.
- Free tier:
- 3 inboxes, 500 emails received and 100 sent a month, with OTP extraction and MCP access.
- Paid:
- Starter $9/mo (10 inboxes, 5,000 received and 2,000 sent a month), Pro $29/mo, Scale $99/mo.
- Better than AgentMail at:
- One long-poll call returns the verification code as a JSON field, the vault keeps the logins the agent creates, and 10 inboxes cost $9 a month against $20.
- Where AgentMail is better:
- The Free plan sends 100 emails a month against AgentMail's 3,000, and AgentMail has a SOC 2 Type II report today while Lumbox does not.
Sources: Lumbox pricing
2Resend Inboxes
Resend's sending API gained Inboxes on October 22, 2026. You create an inbox through the API on a domain you have verified with Resend, receive and reply in threads, and let your agents and your team work the same inbox. Agents connect over the API, CLI or Resend's hosted MCP server, and a built-in inbox agent can draft replies, label, assign and archive threads.
- Who it fits:
- Teams already sending with Resend that want agent inboxes on their own domain, worked by people and agents together.
- Free tier:
- 3 inboxes and 3,000 emails a month (100 a day), shared with all your sending.
- Paid:
- Pro from $20/mo (50,000 emails), with extra inboxes at $1/mo each on paid plans.
- Better than AgentMail at:
- Extra inboxes cost $1 a month against $2, people can assign threads and leave notes in the same inbox, and sending and inboxes come from one vendor.
- Where AgentMail is better:
- Every inbox needs a domain you have verified with receiving enabled, inbox mail counts against your sending quota, and the Inboxes docs list no OTP extraction or wait endpoint.
Sources: Announcing Inboxes, Inboxes docs, Resend pricing
3Nylas Agent Accounts
Nylas-hosted mailboxes and calendars for agents, generally available since June 17, 2026, created through the API, CLI or dashboard on your own domain or a *.nylas.email trial domain. Inbound mail arrives through the message.created webhook, the Nylas CLI reads a recent code with nylas otp get, and the same Nylas account can connect people's existing Gmail and Outlook mailboxes over OAuth.
- Who it fits:
- Products where an agent needs a mailbox and a calendar, or works next to people's own Gmail and Outlook accounts.
- Free tier:
- 3 Agent Accounts, 3,000 agent emails a month and 3 GB of storage.
- Paid:
- Essentials $15/mo (10 Agent Accounts, 10,000 emails, 1 custom sending domain), Pro from $49/mo (50 Agent Accounts).
- Better than AgentMail at:
- The first paid plan is $15 a month against $20, and one API covers agent mailboxes, calendars and human Gmail and Outlook accounts.
- Where AgentMail is better:
- IMAP and SMTP access needs a paid plan, and inbound arrives by webhook or by listing messages, with no wait endpoint.
Sources: Nylas pricing, Nylas Agent Accounts, Agent Accounts GA, nylas otp get
4OpenMail
An email API for agents with send and receive, threading, attachment parsing, inbound sender rules, webhooks and a WebSocket, a CLI, and integrations for LangChain, n8n and the AI SDK. It ships an OpenClaw channel plugin, and all plans are hosted in the EU.
- Who it fits:
- Teams that want AgentMail-style inboxes hosted in the EU at a lower first paid price.
- Free tier:
- 3 inboxes and 3,000 emails a month (100 a day), with 3 GB of storage.
- Paid:
- Pro €9/mo plus usage (10 inboxes, then €1 an inbox; 10,000 emails, then €0.001 an email).
- Better than AgentMail at:
- Pro is €9 a month against $20, extra inboxes are €1 against $2, and every plan is hosted in the EU.
- Where AgentMail is better:
- Its pricing page lists no SOC 2 report and no MCP server.
Sources: OpenMail pricing, OpenMail home
5Robotomail
Two-way mailboxes for agents with an MCP server, a CLI and official SDKs in TypeScript, Python, Go, Ruby and Rust. Inbound mail reaches your code over HMAC-signed webhooks, server-sent events or polling, threading is automatic, and an agent can start its own signup with one POST that a human then verifies by email.
- Who it fits:
- One personal agent that needs its own address for the lowest monthly price.
- Free tier:
- 1 mailbox with 10 sends and 10 receives a month, only with your own verified address.
- Paid:
- Solo $5/mo (1 mailbox, 500 sends and 500 receives), Starter $19/mo (10 mailboxes), Growth $79/mo, Scale $199/mo.
- Better than AgentMail at:
- A $5 plan covers a single mailbox with a custom domain, and Starter allows 15,000 sends a month per mailbox.
- Where AgentMail is better:
- The Free plan cannot email anyone but you, and its docs index lists no OTP extraction or credential vault.
Sources: Robotomail pricing, Robotomail docs index, Agent setup
6Cloudflare Agentic Inbox
Cloudflare Email Routing delivers inbound mail into Workers and Email Sending sends it. Agentic Inbox is Cloudflare's open-source (Apache 2.0) email client on top of both, with a built-in AI agent and an MCP server, deployed to your own Cloudflare account with each mailbox in its own Durable Object and attachments in R2.
- Who it fits:
- Teams that want an open-source, self-hosted AgentMail alternative and already run on Cloudflare Workers.
- Free tier:
- Unlimited inbound routing on Workers Free. Sending to anyone other than your verified addresses needs Workers Paid.
- Paid:
- Workers Paid from $5/mo per account, with 3,000 emails a month included, then $0.35 per 1,000.
- Better than AgentMail at:
- The code is open source, the mail stays in your own Cloudflare account, and inbound routing is unlimited.
- Where AgentMail is better:
- You deploy and secure it yourself, and it has no per-mailbox authorization: anyone past the Cloudflare Access policy, MCP clients included, can reach every mailbox.
Sources: Agentic Inbox, Email Service pricing, Workers pricing
When to stay on AgentMail
- You need a SOC 2 report now. AgentMail includes one on the Startup plan ($200 a month).
- Your agent should sign itself up and email its human before anyone verifies anything. AgentMail's agent signup allows that, while Lumbox and Robotomail keys wait for a human first.
- You build a multi-tenant product and want inbox pods to keep each customer's inboxes and domains apart.
- You want the most widely used option. AgentMail reports more than 10M inboxes and 1B emails processed.
Sources: AgentMail pricing, Agent onboarding, AgentMail home
AgentMail alternatives: frequently asked questions
What is the best AgentMail alternative?
It depends on why you are leaving. Lumbox fits an agent that must read verification codes and log in. Resend Inboxes fits teams already sending with Resend. Nylas Agent Accounts fit an agent that needs a calendar or works beside human mailboxes. OpenMail is the lower-priced EU-hosted option, Robotomail has a $5 single-mailbox plan, and Cloudflare's Agentic Inbox is the open-source one you host yourself.
Is there an open-source AgentMail alternative?
Yes. Cloudflare's Agentic Inbox is open source under Apache 2.0 and runs on your own Cloudflare account, using Email Routing for inbound mail and Email Sending for outbound. You deploy and secure it yourself, and it has no per-mailbox authorization.
Which AgentMail alternative is cheapest?
For one paid mailbox, Robotomail Solo at $5 a month. For 10 inboxes, OpenMail Pro at €9 a month or Lumbox Starter at $9 a month. AgentMail Developer is $20 a month for 10 inboxes, and Nylas Essentials is $15 for 10 Agent Accounts.
Does AgentMail have a free plan?
Yes. AgentMail Free includes 3 inboxes, 1 custom domain and 3,000 emails a month, capped at 100 a day, and adds an AgentMail footer to sent mail. The footer goes away on the $20 Developer plan.
Give your agent its own inbox
Free for 3 inboxes, no card needed.
Start freeSee the head-to-head Lumbox vs AgentMail comparison, or every tool on the alternatives overview.