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Email API for AI agents: inboxes, inbound replies, webhooks, and MCP

By Julien CoulaudPublished June 19, 2026Updated October 24, 20267 min read

We compared 21 options, and one question decides most of the choice. Whose inbox is it? A send-only agent needs a delivery API. An agent acting for a person needs access to their existing inbox. An agent that answers customers needs its own mailbox, inbound events and a way for a person to step in. Prices are in US dollars unless noted, checked on each vendor's site on October 15, 2026. We build Shipmail, and we say below where others are cheaper.

Julien Coulaud on X

Founder of Shipmail, the email platform for businesses and their AI agents. Every guide here draws on mail servers running in production.

  • AI agents
  • Email API
  • MCP
  • Webhooks

Short answer

Pick the API by who owns the inbox. If the agent only sends, a send-only API such as Resend or Postmark is enough. If it acts inside a person's existing inbox, use the Gmail API or Microsoft Graph. If the agent owns conversations, it needs an agent-owned mailbox with inbound webhooks. Use AgentMail or Nylas for many throwaway inboxes, and Shipmail when people share the mailbox.

Choose an email API by the agent workflow

Pick an email API by what the agent does with mail. Support agents, inbound replies and webhook workflows need a hosted inbox with events and threads. Many low-volume identities need cheap inboxes created by API. An agent that only sends needs no mailbox.Sources[1]Shipmail email API for AI agents guide[5]Shipmail webhooks documentation[10]AgentMail email inbox API[16]Nylas Agent Accounts

  • Support agents answering customers: you need a hosted inbox on your domain, inbound webhooks, thread state and a person who can take over. That rules out send-only APIs.
  • Many low-volume inboxes, one per customer, project or agent run: you need cheap inboxes created by API. Per-seat pricing turns every extra identity into another subscription.
  • Inbound replies: you need the parsed message, the thread it belongs to, and idempotent sends so a retry never sends the same reply twice.
  • Webhook workflows: you need signed inbound, delivery and bounce events that wake your code up, instead of a loop that polls the inbox.
Sources[1]Shipmail email API for AI agents guide[5]Shipmail webhooks documentation[10]AgentMail email inbox API[16]Nylas Agent Accounts

If none of these four describes your agent, it does not need a mailbox. A send-only API from the table costs less.Sources[25]Resend pricing[28]Postmark pricing

Best email APIs for AI agents compared

OptionPriceWhat the agent getsBest for
ShipmailSources[1]Shipmail email API for AI agents guide[2]Shipmail MCP server docs[9]Shipmail pricing$4/month for 2 mailboxes; Scale from 13Business mailbox on your domain: REST API, webhooks, MCP, IMAP/SMTP, webmailAgents that answer customers from a mailbox your team also reads
AgentMailSources[10]AgentMail email inbox API[11]AgentMail pricing[12]AgentMail MCP documentationFree for 3 inboxes; $20/mo for 10; $200/mo for 150Inbox API, webhooks, WebSockets, hosted MCP, IMAP/SMTPProducts that create an inbox per user or per task
Nylas Agent AccountsSources[16]Nylas Agent Accounts[17]Nylas pricingFree for 3; $15/mo for 10; $49/mo for 50Email and calendar API, MCP, IMAPAgents that need email and a calendar under one identity
RobotomailSources[19]Robotomail email for AI agents[20]Robotomail pricingFree for 1; $19/mo for 10; $199/mo for 200Mailbox API, hosted MCP, webhooks, event streamOne mailbox per agent, created with one API call
MCPMail[21]Free for 1 mailbox; $12/mailbox/mo with your domainMCP-first hosted mailbox, no documented REST APIAgents that live entirely inside an MCP client
MailRiftSources[22]MailRift email hosting[23]MailRift MCP server documentation[24]MailRift REST API documentationFrom CHF 4.90/domain/mo; MCP from Plus, API from ProHosted mail with webmail, hosted MCP, webhooks, REST APIGermany-hosted business email priced per domain
ResendSources[25]Resend pricing[26]Resend for agents[27]Resend MCP server docsFree for 3,000 emails/mo; $20/mo for 50,000Sending API, inbound receiving, hosted MCPProduct email, with an agent that reads some replies
PostmarkSources[28]Postmark pricing[29]ActiveCampaign postmark-mcp repositoryFree for 100 emails/mo; $15/mo for 10,000Transactional API; inbound on Pro and up; local MCPTransactional sending and bounce checks
MailgunSources[30]Mailgun pricing[31]Mailgun MCP server repositoryFree for 100 emails/day; $15/mo for 10,000Sending API, inbound routes, local MCPTeams already on Mailgun
MailerSendSources[32]MailerSend pricing[33]MailerSend MCP serverFree for 500 emails/mo; $7/mo for 5,000Sending API, inbound routing, hosted MCPLow-volume transactional sending with MCP
MailjetSources[34]Mailjet pricing[35]Mailjet email API[36]Mailjet MCP server announcementFree for 6,000 emails/mo; $9/mo for 8,000Email API, Parse API for inbound, local MCPTeams that send campaigns and transactional email
Mailtrap Email SendingSources[37]Mailtrap pricing[38]Mailtrap MCP serverFree for 4,000 emails/mo; $15/mo for 10,000Email API, testing sandbox, local MCPTesting and staging before an agent sends for real
Cloudflare Email ServiceSources[39]Cloudflare Email Service pricing[40]Cloudflare Email Service overview[41]Cloudflare Email Service for agents3,000 emails/mo on Workers Paid, then $0.35/1,000Email Sending (beta) and Routing for Workers and the Agents SDKAgents already built on Cloudflare Workers
EmailEngine[42]$1,450/year, self-hostedAPI over Gmail, Microsoft 365 and IMAP, webhooks, MCP (beta)Connecting agents to mailboxes you already host elsewhere
Gmail API or Microsoft GraphSources[43]Gmail API overview[45]Microsoft Graph mail API overviewPart of the user's Google or Microsoft accountOAuth mail APIs for an existing inboxAgents acting inside one person's mailbox
Gmail MCP (Google)[44]Developer PreviewReads threads and creates drafts; cannot sendDrafting help inside your own Gmail
Microsoft Work IQ MCPSources[46]Microsoft Work IQ MCP overview[47]Microsoft licensing guidance: Copilot CreditsWork IQ API use billed in Copilot CreditsTenant-scoped tools over Microsoft 365 data, including mailAgents working inside a Microsoft 365 tenant
Nylas CLI MCPSources[18]Nylas CLI MCP guide[17]Nylas pricingNylas plan pricingLocal MCP proxy to Gmail, Outlook, Exchange, Yahoo, iCloud or IMAPDevelopers who want one MCP across many providers
MCPEmails[48]Free for 1 inbox; $9/mo for 3Hosted MCP for existing inboxes; open sourceMCP access to a Gmail, Outlook, Fastmail or IMAP inbox
PortEden Email MCPSources[49]PortEden Email MCP server[50]PortEden pricingFree for 1 identity; Team $59/mo ($49 yearly)Governed hosted MCP for Gmail or Outlook accountsPolicy, audit logs and redaction around an existing inbox
Zoho Mail or FrontSources[51]Zoho Mail REST API[52]Zoho Mail MCP server[53]Front MCP server[54]Front pricingZoho per user; Front from $25/seat/mo yearlyREST API and hosted MCP over mailboxes already in Zoho or FrontTeams already running their mail in Zoho or Front

Agent inbox APIs: AgentMail, Nylas, Robotomail and MCPMail

AgentMail, Nylas, Robotomail and MCPMail create inboxes for software, not for people. Use one when your product gives each user or task its own address and nobody reads those inboxes by hand.

  • AgentMail: Developer is $20 a month for 10 inboxes with custom domains, and Startup is $200 for 150. Events arrive by webhook or WebSocket, so a local agent needs no public URL.
  • Nylas Agent Accounts: email and a calendar under one identity. Essentials is $15 a month for 10 accounts, and Pro is $49 for 50, then $0.40 per account.
  • Robotomail: one API call creates a mailbox. Starter is $19 a month for 10 mailboxes, and Scale is $199 for 200.
  • MCPMail: the agent works through 9 MCP tools, and no public REST API is documented. Team is $12 per mailbox a month with your domain, up to 25.
Sources[11]AgentMail pricing[10]AgentMail email inbox API[16]Nylas Agent Accounts[17]Nylas pricing[19]Robotomail email for AI agents[20]Robotomail pricing[21]MCPMail email for agents

As documented on October 24, 2026, AgentMail has full-text search over messages and threads, ranked by relevance, through REST and the MCP tools search_messages and search_threads. A result page has at most 100 items. AgentMail says retrieved email is untrusted data, so keep it separate from agent instructions.Sources[13]AgentMail Search Messages API reference[14]AgentMail Search Threads API reference[12]AgentMail MCP documentation[15]AgentMail: Introducing Agent Search

AgentMail, Nylas and Robotomail all cost less per inbox than Shipmail once you pass 50 agents. If nobody on your team will open these inboxes, start with one of them.

Business mailboxes with an API: Shipmail and MailRift

With Shipmail and MailRift, the agent's address is an ordinary company mailbox, such as support@ or billing@. People read it in webmail or Apple Mail, and the agent reaches it through an API.

On Shipmail, every plan includes the REST API, webhooks, the MCP server and IMAP/SMTP, starting at $4 a month for 2 mailboxes. A person can assign an agent's conversation to a teammate and leave an internal note, so a handoff stays in one thread.Sources[1]Shipmail email API for AI agents guide[2]Shipmail MCP server docs[8]Shipmail email client connection settings[9]Shipmail pricing

MailRift hosts mail in Germany and prices per domain, from CHF 4.90 a month on Starter. Its MCP server and signed webhooks start on Plus, its REST API on Pro, and IMAP and SMTP access on Enterprise.Sources[22]MailRift email hosting[23]MailRift MCP server documentation[24]MailRift REST API documentation

Sending APIs that also receive: Resend, Postmark, Mailgun and others

Resend, Postmark, Mailgun, MailerSend, Mailjet and Mailtrap are built for product email: receipts, sign-in links, alerts. Each now has an official MCP server, and Resend and MailerSend host theirs.Sources[27]Resend MCP server docs[29]ActiveCampaign postmark-mcp repository[31]Mailgun MCP server repository[33]MailerSend MCP server[36]Mailjet MCP server announcement[38]Mailtrap MCP server

Most can also pass inbound mail to your code. Resend includes inbound on every plan, Mailgun includes 1 inbound route on Free, and Postmark keeps inbound for Pro and Platform. None of them keeps an inbox a person can open.Sources[25]Resend pricing[30]Mailgun pricing[28]Postmark pricing

Cloudflare Email Service fits agents already running on Workers. Inbound routing is unlimited, and sending includes 3,000 emails a month on Workers Paid, then $0.35 per 1,000. It hosts no mailboxes.Sources[39]Cloudflare Email Service pricing[40]Cloudflare Email Service overview

APIs for an existing inbox: Gmail, Microsoft Graph and EmailEngine

The Gmail API, Microsoft Graph and EmailEngine fit when the agent works for one person inside their own mailbox. Gmail and Graph use that person's OAuth grant, so the agent can read everything the account holds.Sources[43]Gmail API overview[45]Microsoft Graph mail API overview

EmailEngine is a self-hosted bridge to Gmail, Microsoft 365 and IMAP for $1,450 a year. It has signed webhooks and an MCP server in beta. Google's Gmail MCP server reads and drafts but has no send tool.Sources[42]EmailEngine email API[44]Gmail MCP server

Zoho Mail, Front, Microsoft Work IQ, MCPEmails, PortEden and the Nylas CLI add MCP access to inboxes you already have. Our email MCP server comparison covers those servers tool by tool.Sources[52]Zoho Mail MCP server[53]Front MCP server[46]Microsoft Work IQ MCP overview[48]MCPEmails hosted email MCP[49]PortEden Email MCP server[18]Nylas CLI MCP guide

What an email inbox costs per agent, from 10 to 300 agents

At 10 agents, an inbox costs $1.50 to $2.00 on AgentMail, Nylas and Robotomail, and the price per inbox drops as you add more. MCPMail charges $12 per mailbox, and the agent-inbox APIs cost less per inbox than Shipmail once you pass 50 agents.Sources[9]Shipmail pricing[11]AgentMail pricing[17]Nylas pricing[20]Robotomail pricing[21]MCPMail email for agents

  • 10 agent mailboxes on Shipmail: $27 a month on Pro plus 6 extra mailboxes, or $2.70 each.
  • 50 agent mailboxes on Shipmail: $125 a month on Scale, or $2.50 each.
  • 150 agent mailboxes on Shipmail: $275 a month on Scale, or $1.83 each.
  • 300 agent mailboxes on Shipmail: $500 a month on Scale, or $1.67 each.
  • AgentMail: $2.00 per inbox at 10 (Developer), $1.33 at 150 (Startup).
  • Nylas Agent Accounts: $1.50 at 10 (Essentials), $0.98 at 50 (Pro), then $0.40 for each extra account.
  • Robotomail: $1.90 at 10 (Starter), $1.58 at 50 (Growth), $1.00 at 200 (Scale).
  • MCPMail: $12 per mailbox, capped at 25 on Team.
Sources[9]Shipmail pricing[11]AgentMail pricing[17]Nylas pricing[20]Robotomail pricing[21]MCPMail email for agents

Shipmail Scale bills $2.50 a mailbox up to 50, then $1.50 for each one after. Each mailbox includes 25 GB and 10,000 sends a month. Self-serve stops at 300 mailboxes.[9]

If your agents' inboxes are disposable, pay the agent-inbox price. If each one is a real company address that customers reply to for months, the extra cost gets you a mailbox people can also work in.

The inbound loop on Shipmail, step by step

Shipmail's inbound loop has five steps: a scoped key, a mailbox, a message.received webhook, checks before the model reads the mail, and a reply sent once with an Idempotency-Key header.Sources[1]Shipmail email API for AI agents guide[5]Shipmail webhooks documentation[7]Shipmail idempotency documentation

  1. Step 1

    Create a scoped key

    In Developer, API keys, give the key only what the agent needs: messages:read, drafts:write for reply drafts, and messages:send only where sending alone is allowed.

  2. Step 2

    Create the mailbox

    Create agent@yourdomain.com with the API, the TypeScript or Python SDK, or the dashboard. It is a normal mailbox, so a person can open it too.

  3. Step 3

    Subscribe to message.received

    Point a webhook at your server. Set authenticated_senders_only to skip senders that fail DMARC, and allowed_senders to accept only known addresses or domains.

  4. Step 4

    Check before the model reads

    Verify the webhook signature, skip event IDs you already handled, and read authentication_results on the message before any text reaches the model.

  5. Step 5

    Draft, then send once

    Save a reply draft for review, or send in the thread with an Idempotency-Key header. Shipmail caches the response for 24 hours, so a retry cannot send twice.

Sources[1]Shipmail email API for AI agents guide[4]Shipmail API authentication documentation[5]Shipmail webhooks documentation[6]Shipmail webhook signature verification[7]Shipmail idempotency documentation

The agent-inbox-starter repository on GitHub runs this loop in Bun and TypeScript, with Claude triage and stale-safe drafts. Sending stays off until you set AUTO_SEND to true.[1]

REST and webhooks or MCP: which should your agent use?

Use REST and webhooks when your code decides what happens: a support pipeline, a billing follow-up, a vendor intake flow. Calls are easy to test, log and retry.

Use MCP when a person drives an agent from Claude, ChatGPT, Cursor or Codex and asks it to check an inbox or draft a reply. Shipmail's hosted server lives at https://shipmail.to/api/mcp and takes the same API key.Sources[2]Shipmail MCP server docs[1]Shipmail email API for AI agents guide

You can run both on the same mailbox, with webhooks for the repeatable path and MCP for the questions nobody scripted.

Limit what the agent can send

Limit an agent's sending with its own mailbox and a key scoped to that mailbox, and start with drafts that a person approves. Send legal, billing, security and account-access mail to a person.Sources[4]Shipmail API authentication documentation[3]Shipmail MCP permissions and security[1]Shipmail email API for AI agents guide

  • Give each agent its own mailbox and its own key, limited to that mailbox, so one leaked key exposes one inbox.
  • Start with drafts. A key with drafts:compose saves new email to Drafts and cannot send it, so a person approves each message.
  • On an MCP connection, pick Read and draft. The MCP server also caps risky tools per session.
  • Escalate legal, billing, security and account-access mail to a person, whatever the model suggests.
Sources[4]Shipmail API authentication documentation[3]Shipmail MCP permissions and security[1]Shipmail email API for AI agents guide

When Shipmail fits, and when it does not

Shipmail fits when the agent answers from a real company address and your team needs to see and take over its conversations. The same account also hosts your own mailboxes and sends your app's transactional email.Sources[1]Shipmail email API for AI agents guide[9]Shipmail pricing

Pick something else in three cases. If you need thousands of disposable inboxes, AgentMail or Robotomail cost less, and Shipmail self-serve stops at 300. If the agent only sends, use a sending API. If the agent works in one person's Gmail, use the Gmail API.Sources[11]AgentMail pricing[20]Robotomail pricing[9]Shipmail pricing[43]Gmail API overview

Sources54 sourcesVerified 2026-11-01
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    Shipmail API keys have scopes and can be limited to specific domains and mailboxes; live and test keys are separate.

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    Every Shipmail webhook delivery is signed with HMAC-SHA256.

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    Monthly list prices: Free is $0 for 3 inboxes, 3,000 emails and 3 GB on agentmail.to. Developer is $20 for 10 inboxes, 10,000 emails, 10 GB, 10 custom domains and 2 organization seats. Startup is $200 for 150 inboxes, 150 custom domains and 10 seats, with no separate monthly email cap, a 15,000-email daily limit, a 1,500-email five-minute limit and unlimited storage. Developer and Startup add inboxes and domains for $2 each, 1,000 monthly sends for $2, and seats for $5 each. Each monthly-sends add-on also raises the daily and five-minute limits. Annual billing is 20% lower.

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    AgentMail documents a hosted MCP server at https://mcp.agentmail.to/mcp and an optional local stdio compatibility bridge. OAuth uses the console identity and API-key access uses x-api-key. The catalog includes inbox, message, thread, draft, attachment and AgentID tools, including the full-text relevance tools search_messages and search_threads.

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    Free: 3 agent accounts. Essentials: $15 a month for 10. Pro: $49 a month (or $43 a month billed annually) for 50, then $0.40 ($0.20 annual) per added account. Enterprise: custom.

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    nylas mcp serve is a local stdio proxy to the hosted Nylas MCP server for Gmail, Outlook, Exchange, Yahoo, iCloud and IMAP accounts.

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    Robotomail creates a mailbox for each agent with one API call. REST API, an official remote MCP server at https://robotomail.com/mcp, webhooks, an SSE event stream, threading, and custom domains with automatic DNS records.

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    Free for 1 mailbox; Starter $19 a month for 10 mailboxes and 1 custom domain; Growth $79 a month for 50; Scale $199 a month for 200.

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    MCPMail is a hosted MCP server that gives agents mailboxes on a shared @mcpmail.bot domain or your own domain. Nine tools: send_mail, reply, list_inbox, read_thread, search, attach, label, wait_for_reply and on_message (a webhook or MCP event stream for incoming mail). Hobby is free for 1 mailbox and 500 sends a month; Team is $12 per mailbox a month with your own domain, up to 25 mailboxes. No public REST API is documented; the docs and SDK links are placeholders.

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    MailRift hosts email on your own domain, priced per domain and hosted in Germany, with webmail, calendar and contacts. Plans read from its live plans endpoint: Starter CHF 4.90 per domain a month (5 mailboxes, no API or MCP), Plus CHF 14.90 (20 mailboxes, MCP and one signed inbound webhook per mailbox), Pro CHF 49 (100 mailboxes, REST API, SDK and account API). The page's static FAQ still lists older Plus and Pro prices. IMAP and SMTP access are Enterprise only.

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    MailRift's REST API at https://api.mailrift.io/v1 with scoped Bearer keys and the @mailrift/sdk TypeScript SDK, available from the Pro plan.

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    Resend pricing page: Free $0 for 3,000 emails a month, at most 100 a day, 3 domains; Pro $20 a month for 50,000 emails or $35 for 100,000, 10 domains; Scale from $90 a month for 100,000 emails, 1,000 domains; extra emails at $0.90 per 1,000 on Pro and Scale with pay-as-you-go; Enterprise on quote. Every plan includes 3 inboxes; more cost $1 per inbox a month on paid plans with pay-as-you-go. Add-ons: 100 more domains for $20 a month on Pro and Scale, a dedicated IP for $30 a month on Scale, SSO for $150 a month on Scale. 30-day data retention below Enterprise. Inbound email, SMTP relay, SDKs and React Email on every plan. The page carries no customer testimonials.

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    Resend for agents

    Resend's agent page: sending, inbound receiving on a verified domain or a resend.app subdomain, and an official MCP server. Free for 3,000 emails a month; Pro $20 a month for 50,000.

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    Resend's MCP server runs remotely at https://mcp.resend.com/mcp with OAuth or an API key, or locally with npx resend-mcp. It can send and read received email. The remote server also has Inboxes tools: create inboxes, search threads, reply to and forward thread emails, and manage labels and drafts. The local package does not include them.

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    Postmark pricing

    Postmark: the free plan sends 100 emails a month with no overage. At 10,000 emails, Basic is $15 (extra $1.80 per 1,000), Pro $16.50 ($1.30) and Platform $18 ($1.20). The slider tiers: Basic $55 at 50,000 and $115 at 125,000; Pro $60.50 and $126.50; Platform $66 and $138. Inbound processing is on Pro and Platform, not Basic. 45-day retention on Basic; Pro and Platform customizable up to 365 days. Responsive templates and a template editor are listed. Dedicated IPs from $50 a month per IP for 300,000 emails a month or more, on Pro or higher. The page quotes people at Asana, Childcare.co.uk, Ten4 Design and Proposify.

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    The official Postmark MCP server, run locally from npm as @activecampaign/postmark-mcp. Its tools send, search outbound mail, and report bounces and delivery stats. It uses a Postmark server token, which cannot be scoped.

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    Mailgun monthly list prices: Free sends 100 emails a day with 1 sending domain, 1 inbound route and 1 day of logs. Basic is $15 for 10,000 emails, no daily limit, 5 inbound routes, extra emails from $1.80 per 1,000. Foundation is $35 for 50,000 and $75 for 100,000, with 1,000 sending domains, a template builder, 5 days of logs and extra emails from $1.30. Scale is $90 for 100,000, $215 for 250,000, $400 for 500,000, $550 for 750,000, $700 for 1 million and $1,250 for 2.5 million, with SAML SSO, dedicated IP pools, 30 days of logs and extra emails from $1.10. One dedicated IP is included from 100,000 emails; extra IPs cost $59 an IP a month.

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    Mailgun's official MCP server, run locally from npm as @mailgun/mcp-server. It sends, retrieves stored messages, manages domains and routes, and exposes no delete operations. Mailgun recommends a dedicated API key.

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    MailerSend monthly list prices, from its pricing page and its pricing.md: Free covers 500 emails a month with 1 domain, 1 template, a drag-and-drop builder and 1 day of activity data. Hobby is a flat $7 for 5,000 emails with 5 seats, 1 domain and 10 templates; extra emails $1.50 per 1,000. Starter is $35 for 50,000, $68 for 100,000 and $162.50 for 250,000, with 10 domains, 250 templates, 7 days of data, SMS in the USA and Canada and 50 webhooks; extra emails $1.30 per 1,000. Professional is $110 for 50,000 and $140 for 100,000, with unlimited users, domains and templates and 30 days of data. Inbound routing on every plan. Yearly billing saves 10%. Nonprofits get 30% off.

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    Mailjet: Free sends 6,000 emails a month, at most 200 a day. Starter is $9 a month for 8,000 emails, billed monthly.

    mailjet.com · 2026-10-15

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    Mailjet's transactional and marketing email API. Free for 6,000 emails a month (200 a day); Starter from $9 a month. The Parse API for inbound mail needs a Premium plan.

    mailjet.com · 2026-10-12

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    Mailjet's official open-source MCP server, announced October 31, 2025. It runs locally and is read-only by default.

    mailjet.com · 2026-10-12

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    Mailtrap Email API/SMTP: Free sends 4,000 emails a month with no card. Basic is $15 a month for 10,000 emails.

    mailtrap.io · 2026-10-15

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    Mailtrap's official MCP server, run locally with npx or as a Claude Desktop extension, for sending, sandbox messages and templates. Mailtrap is free for 4,000 emails a month; Basic starts at $15 a month.

    docs.mailtrap.io · 2026-10-12

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    Email Routing inbound is unlimited on Workers Free and Paid. Sending to verified destination addresses is free on all plans. Sending to any recipient needs Workers Paid: 3,000 emails a month included, then $0.35 per 1,000.

    developers.cloudflare.com · 2026-11-01

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    Cloudflare Email Service overview

    Email Routing (Free and Paid plans) routes incoming mail to addresses or Workers. Email Sending is in beta for outbound transactional email on Workers Paid, through a Workers binding, the REST API or authenticated SMTP. No hosted mailboxes are described.

    developers.cloudflare.com · 2026-11-01

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    blog.cloudflare.com · 2026-10-12

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    emailengine.app · 2026-10-15

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    Official Gmail API overview for authorized access to Gmail mailbox data.

    developers.google.com · 2026-07-29

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    Google's official remote Gmail MCP server, in Developer Preview. Its tools create and list drafts, read and search threads, and manage labels. It cannot send; the user sends drafts from Gmail.

    developers.google.com · 2026-10-15

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    learn.microsoft.com · 2026-07-29

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    Work IQ MCP, in preview, is one Microsoft 365 endpoint with generic tools that read and act on tenant data such as mail; writes are off until an admin enables them. Copilot Studio bills it in Copilot Credits.

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    PortEden's hosted, governed email MCP server for existing Gmail and Outlook/Microsoft 365 accounts: per-tool policy, read-only mode, contact and domain blocks, confirm-before-send, audit logs and PII redaction. Free for 1 identity and 1,000 requests a month; Team $49 a month.

    porteden.com · 2026-10-15

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    PortEden: Free covers 1 protected identity, 2 active agents and 1,000 requests a month. Pro is $10 a month ($8 billed yearly) for 3 identities. Team is $59 a month ($49 billed yearly) for 5 identities and 500,000 requests. Enterprise is custom.

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    zoho.com · 2026-10-12

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    Zoho Mail's official remote MCP server, set up in the Zoho MCP console, with tools to send, read and reply, manage folders and labels, settings, tasks and admin objects. Zoho says it is free on free and paid Mail plans.

    zoho.com · 2026-10-15

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    Front MCP server

    Front's official remote MCP server at https://mcp.frontapp.com/mcp. It searches and reads conversations, creates drafts, sends with the send scope, comments, assigns and tags. Each token acts with one Front teammate's permissions.

    dev.frontapp.com · 2026-10-15

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    Front pricing

    Front, per seat a month: Starter $25 billed annually or $35 monthly (up to 10 seats, one channel type of email, chat or SMS, up to 10 automation rules, basic analytics, a basic knowledge base, one workspace); Professional $65 billed annually or $85 monthly (up to 50 seats, omnichannel email, SMS, social and WhatsApp, macros and 20 rules, advanced analytics, up to 5 workspaces, SSO and SCIM); Enterprise $105, annual billing only (unlimited rules and macros, custom roles, multi-language knowledge base, Copilot, Smart QA and Smart CSAT included). Annual billing saves 24%. Assignments, internal comments, shared drafts and message templates on every plan. Add-ons: Copilot $20 per seat a month on Starter and Professional; Autopilot from $0.05 a conversation; native WhatsApp at Meta's cost plus a 20% fee on Professional and Enterprise; an API rate limit increase at $200 per 100 requests a minute a month. Seats cannot be mixed across plans. 14-day trial of Professional without a card, no free plan. An onboarding package is required for contracts over $25,000.

    front.com · 2026-11-01

Questions worth answering

Common questions about email API for AI agents.

What is the best email API for AI agents?
It depends on who reads the inbox. For disposable inboxes created by the hundred, AgentMail or Robotomail. For an agent that only sends, Resend or Postmark. For an agent that answers customers from a company address your team also reads, Shipmail.Sources[11]AgentMail pricing[20]Robotomail pricing[25]Resend pricing[1]Shipmail email API for AI agents guide
How much does an email inbox for an AI agent cost?
From under $1 to $12 a month per inbox. Nylas Pro works out at $0.98 each for 50, and MCPMail charges $12 per mailbox. On Shipmail, $125 a month covers 50 agent mailboxes.Sources[20]Robotomail pricing[21]MCPMail email for agents[9]Shipmail pricing
Can an AI agent have its own email address on my domain?
Yes. Create a mailbox such as agent@yourdomain.com, give the agent a key limited to that mailbox, and subscribe to inbound events. Keep it separate from your personal inbox, so the agent never sees mail it does not need.Sources[1]Shipmail email API for AI agents guide[4]Shipmail API authentication documentation
Should an AI agent use MCP or the REST API for email?
Use REST and webhooks when your code runs the workflow, because calls are easy to test and retry. Use MCP when a person drives the agent from Claude, ChatGPT or Cursor. Both can point at the same mailbox and key.[2]
How do I stop an email agent from acting on spoofed or injected mail?
Check DMARC before the model reads anything, accept mail only from an allowlist where you can, and strip links and hidden text from the body. Start with drafts that a person sends, and turn on direct sending per workflow later.Sources[5]Shipmail webhooks documentation[1]Shipmail email API for AI agents guide
Can I use Resend or Postmark for an AI agent?
Yes, if the agent mostly sends. Resend receives inbound on every plan and Postmark on Pro and up, but both pass mail to your code. Neither keeps an inbox a person can open and reply from.Sources[25]Resend pricing[28]Postmark pricing

Related guides

More on Shipmail pricing, comparisons, and team workflows.

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