Best email for AI agents: services compared
An AI agent needs email for many jobs: sign-up codes, invoices, client briefs, alerts and replies. There are four ways to give it an address, and each one fits a different job:
- Agent inbox services give each agent its own mailbox through an API and an MCP server.
- Inbound email APIs turn incoming mail into a webhook for an app you already run.
- Your own mailbox, such as Gmail, gives the agent your existing mail and address.
- Self-hosted software runs the mailbox layer on your own servers.
This page compares the main email services for AI agents in each group.
Short answer
| Your agent needs to | Look at |
|---|---|
| Receive documents, codes and alerts, keep files and scan mail for malware and label suspected prompt injection | Revdoku |
| Email people first and run long two-way threads | AgentMail, Robotomail, Nylas Agent Accounts |
| Use a business mailbox on your own domain | Hostinger Agentic Mail |
| Process inbound mail inside an app you already run | Postmark, Resend, Mailgun, SendGrid |
| Handle mail on a domain that already uses Cloudflare | Cloudflare Email Routing |
| Work with your existing inbox and its history | Gmail API |
| Keep the whole mailbox layer on your own servers | NornWeave |
Agent inbox services
These services give each agent an email inbox it can use right away, with an email API and, for most, an MCP server for AI apps. They are also the usual AgentMail alternatives.
Plans and sending
| Service | Free plan | Paid plans from | Can email people first |
|---|---|---|---|
| Revdoku | Free to try | See pricing | No; it replies to people who wrote |
| AgentMail | 3 inboxes, 3,000 emails a month; sent mail carries a “Sent via AgentMail” footer | $20 a month | Yes |
| Robotomail | 1 mailbox; mail only between the agent and your verified address | $5 a month | Yes, on paid plans |
| Nylas Agent Accounts | 3 accounts, 3,000 emails a month | $15 a month | Yes |
| Mailtrap | 4,000 emails a month, sent and received; a hosted inbox can send only 20 replies in total until you add your own domain | $15 a month | Yes |
| Hostinger Agentic Mail | No; 30-day money-back guarantee | $0.39 a month per mailbox on a 48-month term, paid upfront; renews at $1.59 a month | Yes |
| Resend Inboxes | Private beta; 3 inboxes, mail counts toward the Free plan’s 3,000 emails a month | $20 a month (Pro); $1 a month per extra inbox | Yes |
Integration and safety
| Service | New mail alerts | MCP server | Security and data |
|---|---|---|---|
| Revdoku | Signed webhook, WebSocket or polling | Hosted, sign-in in the browser | Malware scan, known spammers blocked, prompt-injection labels; activity log; EU region |
| AgentMail | Webhooks, WebSockets or polling | Hosted, OAuth or API key | Spam and virus scanning; SOC 2 Type II; EU region on Enterprise |
| Robotomail | Signed webhooks, server-sent events or polling | Hosted, OAuth | Malware scanning not provided, per its guide |
| Nylas Agent Accounts | Webhooks, IMAP | Hosted, US and EU endpoints | SOC 2 Type II, ISO 27001; HIPAA BAA on Enterprise |
| Mailtrap | Signed webhooks or polling | Local, runs with npx | SOC 2 Type II; data regions coming soon |
| Hostinger Agentic Mail | Webhooks | Coming soon, per its FAQ | Spam, virus and phishing protection; audit logs |
| Resend Inboxes | Webhooks | Hosted, OAuth | SOC 2 Type II on every Resend plan |
Inbound email APIs
These services receive mail for a domain or address and pass it to your app. You build the storage, queue and agent around them.
| Service | Free tier | How mail reaches your app | Attachments |
|---|---|---|---|
| Postmark | Inbound is listed on the Pro and Platform plans | Parsed JSON webhook, retried for about 10 hours | Base64 in the JSON, up to 35 MB in total |
| Resend | 3,000 emails a month and 100 a day, received mail included | Webhook with metadata only; body and attachments through the API | Download links valid for 1 hour |
| Mailgun | 100 emails a day, 1 route | Routes forward to a webhook as form data, JSON or raw MIME | In the webhook |
| SendGrid | 60-day trial | Inbound Parse posts form data or raw MIME | Whole message up to about 30 MB |
| Cloudflare Email Routing | Inbound routing is free | A Worker receives the raw message | Whole message up to 25 MiB; you parse it |
Cloudflare needs your domain on Cloudflare DNS. Its sending service is in public beta on the Workers Paid plan.
Your own mailbox: Gmail API
The Gmail API lets an agent read your existing mail and send from your address.
- Permissions: reading mail needs a restricted scope, such as
gmail.readonly, that covers the whole mailbox. A public app that keeps this data on its servers needs Google verification and a yearly security assessment. - New mail alerts: Pub/Sub notifications that you renew every 7 days, with polling as a fallback.
- Cost: the API is free within its quotas. Each extra mailbox is a Google Workspace user, from $7 a month on an annual plan.
- MCP: Google’s Gmail MCP server is in developer preview.
Self-hosted: NornWeave
NornWeave is open-source software under the Apache 2.0 license. You run it on your own servers, on top of Mailgun, Amazon SES, SendGrid, Resend or an IMAP/SMTP account. It has a REST API, an MCP server and attachment storage on your own disk or bucket. You also run the servers, backups and spam filtering.
Where Revdoku fits
Revdoku is built for agents that receive email. Every mailbox keeps each attachment as a file and lets several agents share the same mail and files, each with its own access. Incoming mail is scanned for malware, known spammers are blocked, and emails with suspected malicious prompts are labeled Junk. An agent can reply to people who wrote to it, but it does not start new conversations. If that is your main job, a two-way service fits better.
Create a mailbox from $4.99/mo, or try it free, then connect your AI app from the list of apps.
Side-by-side pages: AgentMail, Robotomail, Gmail.
Email address
for your AI agent
[email protected] address
to receive emails, send replies
and store attachments and files.
- Built-in virus, malware and spam filter
- AI labels for suspected prompt injection
- Built-in secure file storage
- Read, send, manage via API, MCP, CLI
From $4.99/mo · 30-day money-back guarantee on your first payment
or Try free: 1 mailbox, replies only to you, no card
Details about other products were checked on October 17, 2026 against their public websites and docs. They can change.
Frequently Asked Questions
What is the best email service for AI agents?
It depends on the job. For agents that receive documents, codes and alerts, a mailbox service such as Revdoku fits. For agents that must email people first, look at AgentMail, Robotomail or Nylas Agent Accounts. For an app you already run, an inbound API such as Postmark or Resend may be enough.
What are the main AgentMail alternatives?
Revdoku, Robotomail, Nylas Agent Accounts, Mailtrap, Hostinger Agentic Mail and Resend Inboxes all give agents their own inboxes. Inbound APIs such as Postmark, Mailgun, SendGrid and Cloudflare Email Routing are options when you build the rest of the pipeline yourself.
Can I give an AI agent email for free?
AgentMail, Nylas Agent Accounts and Mailtrap have free plans, with different limits. Revdoku is free to try. Robotomail’s free plan only exchanges mail with your own verified address, and Cloudflare Email Routing receives mail for free on a domain that uses Cloudflare DNS.
Should my agent use Gmail instead?
Use Gmail when the agent needs your existing mail or must send from your address. Reading mail needs a scope that covers the whole mailbox, and a public app that stores the data on its servers needs Google verification and a yearly security assessment.
Which services check incoming email for malware or prompt injection?
Revdoku scans incoming mail for malware, blocks known spammers and labels suspected malicious prompts as Junk. AgentMail scans for spam and viruses and has a prompt-injection feature in its Labs. Robotomail’s guide says not to treat its downloads as malware-scanned.
Can Revdoku send email to anyone?
No. A Revdoku agent replies to people who emailed its mailbox, and it does not start new conversations. If your agent must email people first, a two-way service such as AgentMail, Robotomail or Nylas fits better.