# Resend Inboxes Gives AI Agents Threaded Email, With Shared Quotas

Resend's new Inboxes adds conversation state, team handoffs and agent controls. Here is what developers need to know about setup and pricing.

By Paras Madan | 2026-10-24


Resend [announced Inboxes on October 22](https://resend.com/blog/announcing-inboxes), giving applications and AI agents shared email addresses with threaded conversations. Developers can connect their own agents or configure Resend's built-in agent to handle incoming mail.

The useful change is what happens after an email arrives. A support agent needs to know which conversation it belongs to, whether a person has taken over, and what has already been said. Keeping that state consistent can require more application code than the initial model call.

## Conversation state becomes part of the service

Resend's [Inboxes documentation](https://resend.com/docs/dashboard/inboxes/introduction) distinguishes the new product from its existing inbound-email feature. Ordinary receiving delivers messages to your webhook. Inboxes stores and organizes conversations, with threads, drafts, labels and teammate assignments accessible through the dashboard or programmatically.

For a developer, that changes the integration boundary. A custom agent can work against a shared conversation record instead of maintaining a separate email history that a support team cannot see. The practical benefit will depend on how well the application handles ownership when a person and an agent both work on the same request.

The launch also includes configurable agent actions, such as drafting replies, labeling, forwarding, assigning threads and deleting messages. Resend recommends starting with drafts and labels before allowing more actions. That is a sensible rollout path for customer-facing workflows: review the proposed reply before giving the system permission to act more broadly.

## Connecting an agent still requires a permissions decision

The [MCP documentation](https://resend.com/docs/mcp-server) describes a hosted server using Streamable HTTP and an OAuth approval flow. A local MCP server is also available. Teams with an existing agent can therefore connect email tools without adopting Resend's built-in agent as their orchestration layer.

For an initial deployment, I would keep the task narrow: classify incoming support requests and prepare replies for a person to review. Email content should be treated as outside input, not as permission to change the agent's instructions or disclose another customer's information. Test that boundary with deliberately misleading messages before allowing automatic forwarding or replies.

Address setup also deserves a check. The [creation guide](https://resend.com/docs/dashboard/inboxes/create-inboxes) requires a verified sending domain. Receiving normally needs an MX record, but forwarding is supported when an existing mail provider already owns that route. The API can provision a receiving address with forwarding enabled, avoiding an unnecessary change to the company's existing mail setup.

## Three inboxes does not mean three separate email allowances

Resend's [pricing page](https://resend.com/pricing) includes three inboxes on its standard plans. Paid subscriptions with pay-as-you-go enabled can add inboxes for $1 each per month. Every email sent or received through an inbox counts toward the same transactional email quota.

Free lists 3,000 emails per month and a 100-email daily limit. Pro starts at $20 per month for 50,000 emails, without the daily email cap. At that base tier, ten inboxes would mean $27 per month before email overages or other charges: $20 for Pro and $7 for seven additional inboxes.

The planning unit should therefore be conversations and message volume, not just the number of agents. A busy support exchange can consume several messages while using one address. Measure how many drafts need correction and how often people take over, too. Those results will tell you more about deployment readiness than a successful first reply.

I'm Paras. I work at the intersection of AI, engineering and distribution.

I help technical founders explain agent products through clear integration stories, practical limitations and the decisions developers need to make.

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