You want your AI agent to send and reply to email like a real teammate. Not as you, with your name on the From line. As itself, with its own address, its own inbox, and its own audit trail. That requires more than an SMTP key.
An AI agent needs three things from an email inbox: a persistent address it owns, two-way send and receive via API or webhook, and programmatic provisioning that does not require a human in a UI. Generic email providers like Gmail require OAuth flows and manual setup. Transactional APIs like SendGrid have no per-agent address primitive. Bavimail bundles the inbox layer natively starting at $4 per month, with 10,000 emails included and both inbound and outbound on every plan.
The shortest path looks like this. Bavimail provisions a per-agent inbox alias with one POST to /aliases on a verified domain. The agent then receives every inbound reply as a signed webhook (HMAC-SHA256) with parsed body, headers, and attachments delivered as pre-signed URLs. Three requirements, one product surface, under five minutes from API key to first reply parsed by your agent.
What does an AI agent actually need from an email inbox?
Start with the agent's job to be done. If your agent follows up on leads, schedules demos, handles support tickets, or coordinates with vendors, outbound messages are not enough. It needs to own the conversation.
That comes down to four properties of a real ai agent email inbox:
- A persistent per-agent inbox tied to a real domain you control, so recipients can reply and the agent can keep state across turns.
- Two-way email for AI, meaning send through an API and receive parsed inbound through a webhook in the same product.
- Programmatic provisioning, so spinning up the hundredth agent does not require a human to log into a console.
- Identity isolation, so each agent has its own address (think agent-onboarding, billing-bot, support, research-1) and your audit logs stay clean.
This is the agent email identity layer. Without it, you bolt an inbox onto a sending API and write the glue yourself.
Why do generic email providers and transactional APIs fall short?
Gmail and Google Workspace look free until you scale agents. Every mailbox is a licensed seat. Provisioning requires the admin console or a delegated service account, and sending from an agent requires an OAuth refresh token per agent that you have to store, rotate, and recover when it expires. Receiving means polling IMAP or wiring up Pub/Sub. Nothing about it was designed for programmatic identity.
Transactional APIs like SendGrid, Postmark, and Resend solve outbound at scale but stop at the From line. They ship no first-class per-agent inbox primitive. If a recipient replies, the message goes to whatever mailbox is configured at your DNS provider, not back to the API. To close the loop, you have to add an inbound parser like CloudMailin, build your own routing, and reconcile it with the outbound side.
Pure outbound stacks did not anticipate agents that need to listen.
How do you provision a per-agent inbox in under 5 minutes?
The full setup is a four step path. Add and verify a domain, mint an API key (the prefix is bm_, so it is grep-friendly in your logs), create an alias for the agent, and point a webhook URL at the agent's handler.
Domain verification runs fully programmatically. Bavimail checks SPF, DKIM, DMARC, and MAIL FROM records via the API and reports back. You wait on no support ticket and guess at no DNS records. Once the domain is verified, every alias you create on it inherits the deliverability posture.
Creating an alias is one POST to /aliases with a local part and the verified domain. The response gives you the full address (for example agent-7 at yourdomain.com) and an alias ID you can store on the agent record. From that moment, the alias can send via POST /emails and can receive any message addressed to it, including replies to messages the agent already sent. There is a full walkthrough with a working request and response on the agent onboarding guide.
How does the agent receive replies and handle attachments?
Inbound goes through webhooks. Bavimail emits 13 event types covering the full lifecycle: delivered, opened, clicked, bounced, complained, replied, and the inbound events that carry actual message bodies into your agent.
Bavimail signs every webhook with HMAC-SHA256 and includes a timestamp. Your handler should verify the signature against your webhook secret and reject any request with a timestamp older than 5 minutes. That window is short enough to block replay attacks and long enough to tolerate normal network jitter.
The payload arrives already parsed. You get the From, To, subject, plain text body, HTML body, and a list of headers. Attachments are not inlined as base64. Bavimail uploads them to object storage and delivers pre-signed URLs scoped to short expirations. Your agent fetches what it needs, and large files never bloat the webhook payload. The full schema, signature verification example, and event reference live on the webhooks reference.
For agents built on MCP, Bavimail also ships an MCP server with 12 tools covering both sending and inbox actions. Inbound content arrives wrapped in an untrusted-third-party-content marker so your model knows the difference between an instruction from you and a string a stranger emailed your agent.
What does this cost, and what is included?
The Pro floor is $4 per month and includes 10,000 emails. Every plan, including the floor, includes both inbound and outbound. There is no separate fee to receive replies and no upgrade gate to use the inbox layer. Per-agent aliases on a verified domain are a native primitive, not an add-on.
That matters when you run dozens or hundreds of agents. Adding the hundredth agent is one alias create. Adding the thousandth is one alias create. The marginal cost is the email volume itself, not the inbox.
Where should I start?
If you have been duct-taping Gmail OAuth, polling IMAP, or stitching a transactional API to a third-party inbound parser, this is the consolidation point. One API key, one webhook, one bill, and an inbox primitive designed for agents from day one. Open the agent onboarding guide, provision your first alias, and have your agent reading replies before your coffee finishes brewing.