Provision email for an agent fleet (agencies)

The governance model first

For an agency, the governance and isolation model is the buying decision, so lead with it:

• One tenant, many mailboxes. Provision a mailbox per client agent under a single account.
• Per-mailbox scoped keys. Each agent gets an sm_live_… key scoped to one mailbox, with a read / read_write role and an optional expiry - least privilege per agent, revocable one at a time.
• `sm_mgmt_` management key. A tenant-wide key for cross-mailbox operations across the mailboxes you own - dashboard-issued, never agent-callable, so a leaked agent key can't administer the fleet.
• Per-customer encryption + isolated suppression. Each client's mailbox is encrypted with its own key; bounces, complaints, and limits are tracked per mailbox, so one client's behavior never affects another's deliverability.
• Instant mailboxes on Sairaph domains, or BYO. Provision each client's mailbox on sairaph.email, sai.email, or sent.ac instantly, no DNS - or connect a client's own domain with DNS verification for an on-brand address.
• A UI to hand over. The management dashboard lets a human (yours or the client's) watch what each agent sent and received.

The problem: a fleet multiplies every email headache

Doing this by hand means a registrar, DNS, DKIM/SPF/DMARC, an SMTP relay, an IMAP loop, and a secrets store - per client. Multiply that by a roster of clients and you've built an email operations team instead of shipping agents. And a shared sender can't isolate clients, can't be revoked per client, and can't be encrypted per client. A fleet needs a governance model, not a pile of mailboxes.

How it works

1. Provision a mailbox per agent. Create a mailbox for each client agent instantly on a Sairaph domain (sairaph.email, sai.email, sent.ac), no DNS - or on a client's connected, DNS-verified domain if they want a custom address.
2. Scope a key to each. Issue a per-mailbox sm_live_… key with the right role and expiry; revoke a single client without touching the rest. Snippet: KEY_USAGE.
3. Govern from one tenant. Use an sm_mgmt_ management key for cross-mailbox operations across the fleet, while each agent stays scoped to its own mailbox.
4. Keep clients isolated. Per-customer encryption plus per-mailbox suppression and limits mean one client can't affect another.
5. Hand off visibility. Give a client the dashboard view of their own mailbox(es) so they can see what their agent is doing.

API / MCP touchpoints

• Per-client send/read: POST /api/v1/mailboxes/{mailbox_id}/outbound, GET /api/v1/mailboxes/{mailbox_id}/messages - each scoped to one client's mailbox. Snippets: SEND_CURL, READ_INBOUND_CURL.
• Keys: per-mailbox sm_live_… per agent; tenant-wide sm_mgmt_… for cross-mailbox ops. Dashboard-issued only - snippet KEY_USAGE.
• MCP: each client agent connects to /mcp/v1/mcp with its own scoped key, so the tool surface is isolated per client.

Why an owned, two-way mailbox per agent beats the alternatives

Reselling a shared transactional sender means no per-client isolation, no per-client revocation, no per-client encryption, and no inbox for the agent to read. A real owned mailbox per agent gives you a hard isolation boundary and a two-way inbox, governed from one tenant with a management key - the difference between operating a fleet and operating a liability.

FAQ

How do I manage the whole fleet at once? An sm_mgmt_ management key is tenant-wide and spans the mailboxes you own for cross-mailbox operations, while each client's agent uses a key scoped to just its mailbox.

Can a client use their own domain? Every client already gets an instant mailbox on a Sairaph domain (sairaph.email, sai.email, sent.ac), no DNS needed. If they want a custom address, connect their domain with DNS verification so their mail is on-brand.

Can I revoke or expire one client without affecting the rest? Yes. Each per-mailbox key is independent; revoke or expire one and the others keep working.

Are clients isolated from each other? Each client's mailbox is encrypted with its own per-customer key, and suppression and limits are tracked per mailbox, so one client can't affect another.

Can I give a client visibility? Yes - the management dashboard shows a mailbox's sent and received mail, so a human on your side or the client's can watch the agent.

Related

• A mailbox per customer - the multi-tenant SaaS version of this model.
• For agencies - fleet governance and client handoff.
• Talk to us - fleet volume and the DPA.

CTA: Talk to us - provision and govern a fleet of agent mailboxes. Secondary: A mailbox per customer.