Use AgentRouter to send email, buy inboxes, receive replies, and manage branded subdomains across multiple providers through one API.
StableEmail
AgentMail
Inkbox
Resend
SendGrid5
Live Providers
52
Live Routes
0 credits ($0)
Send Starts At
0 credits ($0)
Inbox Acquisition
As of April 16, 2026, the live email catalog exposes 23 capabilities for AI agents. Shared sender delivery starts at 0 credits ($0), branded subdomain setup starts at 5000 credits ($5), and recommendation can surface cheaper recurring owned-inbox routes when setup is required first.
Availability Note
AgentMail MPP inbox metadata reads are temporarily unavailable. AgentMail create and send routes still work, but inbox status and inbox message list over MPP are currently degraded.
What Is Agent Email?
Agent email is the operational layer that lets an AI agent own an inbox, send outbound email, receive replies, and manage its sender identity programmatically. For most production agents, email is not only outbound delivery. It also includes address ownership, message inspection, retention, forwarding, and branded sender setup.
Direct provider integrations usually split these jobs across multiple APIs. One provider may be good at outbound send, another at inbox ownership, and another at branded domain workflows. That fragmentation is exactly what searchers looking for `agent email` or `email API for AI agents` are trying to avoid.
AgentRouter turns those moving parts into one routed surface. You can compare providers, recommend a route before execution, buy inboxes, inspect replies, top up mailbox lifetime, and move into branded subdomain workflows without rebuilding the integration every time the provider mix changes.
Top Scenarios
Route transactional or workflow-triggered email without hard-coding one provider before execution.
Inkbox
Direct
StableEmail
AgentCash
AgentMail
MPP
Notifications, status updates, and outbound agent workflows
Coverage: 1 capabilities · 9 live routes
Start with Send
Provider Comparison
All providers below are available through AgentRouter. The comparison is based on the live email route catalog on April 16, 2026.
| Provider | Best For | Key Capabilities | Starting Price | Available Via |
|---|---|---|---|---|
StableEmail Covers inbox ownership, inbox topups, branded subdomains, and the broadest managed email capability set. 26 live routes | Owned inboxes, branded subdomains, and long-running email agents | Send, Inbox Acquire, Inbox Status, Inbox Update +19 more Modes: Managed, BYO | 0 credits ($0) | AgentCash |
AgentMail Covers send, inbox acquisition, inbox reads, and message operations through direct and MPP routes. 15 live routes | Agent-native inbox and send flows |
Quick Start
The fastest path is the same install flow used on the AgentRouter homepage: get an API key, ask for a route recommendation, and execute the email capability through one wallet.
Step 1
Get your API key
Enable AgentRouter once, then reuse the same key across send, inbox, and subdomain email capabilities.
Step 2
Recommend the route
Let AgentRouter compare current routes, pricing, and prerequisites before the first execute call.
Step 3
Execute the capability
Send email, buy an inbox, top up lifetime, or provision a branded subdomain through the selected route.
Works with
Pricing By Task
These examples translate route prices into common workflow questions that search visitors usually ask before integrating.
| Task | Route | Price | Notes |
|---|---|---|---|
| Send 1 email right now | Resend (email.send.resend) | 10 credits ($0.01) | Managed direct send with no inbox purchase prerequisite. |
| Send 100 emails right now | Resend (email.send.resend) | 1000 credits ($1) | Simple volume estimate based on the current live Resend managed route. |
Pricing note: 1000 credits = $1 USD. Raw API responses still return numeric credit fields such as creditsCharged.
Why AgentRouter
One API covers direct send routes, inbox acquisition, inbox reads, inbox lifetime management, branded subdomains, and branded subdomain inboxes. Recommendation happens before execution, so the agent can compare current route prices and prerequisites instead of hard-coding one provider forever.
FAQ
Agent email means giving an AI agent the ability to send email, own an inbox, receive replies, and manage its email identity programmatically. On AgentRouter, that includes outbound send, inbox acquisition, inbox reads, inbox topups, branded subdomains, and subdomain inbox operations.
Yes. The email domain covers send routes plus inbox acquisition, inbox status, inbox message list, inbox message read, and inbox message delete. That lets one agent send mail, inspect replies, and continue the workflow from the same API surface.
Start with the email inbox acquire capability. AgentRouter exposes live inbox purchase routes, prices them in credits, and returns the acquired address so later send, status, topup, and message operations can reference the same inbox.
As of April 16, 2026, the live catalog starts managed send at 10 credits on Resend and 10 credits on AgentMail MPP. StableEmail owned-inbox send can be cheaper at 5 credits, but that route depends on already owning the inbox first.
Use a branded subdomain when the agent needs a dedicated sender namespace, branded inboxes, signer controls, or stronger separation between multiple agents and teams. Shared sender routes are simpler when the job is only one-off outbound delivery.
AgentRouter can surface acquisition-first workflows during recommendation. That means the page can show both the cheapest route you can execute immediately and the cheaper recurring route available after the inbox is provisioned.
Reference
Use the capability browser below when you want the contract-level detail: endpoints, live example modals, route breakdowns, and exact route prices.
AgentRouter·
·
| Capability | Endpoints | Price |
|---|---|---|
send Send outbound email through the best route for the requested sender model, pricing, and settlement constraints. | GET /api/agentic-api/domains/email/capabilities/sendRead the capability contract, current lifecycle status, and machine-readable metadata for this email capability. | Free |
POST /api/agentic-api/domains/email/capabilities/send/recommendAsk AgentRouter to compare eligible routes inside this capability and return the best recommendation before execution. | Free | |
POST /api/agentic-api/domains/email/capabilities/send/executeExecute this capability through the selected route while AgentRouter handles pricing, wallet debits, and upstream settlement. | ||
inbox.acquire Acquire or provision an inbox for forwarding, programmatic message access, and future sending from the inbox address. | GET /api/agentic-api/domains/email/capabilities/inbox-acquireRead the capability contract, current lifecycle status, and machine-readable metadata for this email capability. | Free |
POST /api/agentic-api/domains/email/capabilities/inbox-acquire/recommendAsk AgentRouter to compare eligible routes inside this capability and return the best recommendation before execution. | Free | |
POST /api/agentic-api/domains/email/capabilities/inbox-acquire/executeExecute this capability through the selected route while AgentRouter handles pricing, wallet debits, and upstream settlement. | ||
inbox.status Inspect inbox state, delivery settings, balance, or readiness before using the inbox. | GET /api/agentic-api/domains/email/capabilities/inbox-statusRead the capability contract, current lifecycle status, and machine-readable metadata for this email capability. | Free |
POST /api/agentic-api/domains/email/capabilities/inbox-status/recommendAsk AgentRouter to compare eligible routes inside this capability and return the best recommendation before execution. | Free | |
POST /api/agentic-api/domains/email/capabilities/inbox-status/executeExecute this capability through the selected route while AgentRouter handles pricing, wallet debits, and upstream settlement. 1 route in this breakdown are temporarily unavailable. | ||
inbox.topup Add funds or credits to an inbox so it can remain active and continue supporting inbox-linked flows. | GET /api/agentic-api/domains/email/capabilities/inbox-topupRead the capability contract, current lifecycle status, and machine-readable metadata for this email capability. | Free |
POST /api/agentic-api/domains/email/capabilities/inbox-topup/recommendAsk AgentRouter to compare eligible routes inside this capability and return the best recommendation before execution. | Free | |
POST /api/agentic-api/domains/email/capabilities/inbox-topup/executeExecute this capability through the selected route while AgentRouter handles pricing, wallet debits, and upstream settlement. | ||
inbox.update Update inbox configuration such as forwarding or other mutable inbox settings. | GET /api/agentic-api/domains/email/capabilities/inbox-updateRead the capability contract, current lifecycle status, and machine-readable metadata for this email capability. | Free |
POST /api/agentic-api/domains/email/capabilities/inbox-update/recommendAsk AgentRouter to compare eligible routes inside this capability and return the best recommendation before execution. | Free | |
POST /api/agentic-api/domains/email/capabilities/inbox-update/executeExecute this capability through the selected route while AgentRouter handles pricing, wallet debits, and upstream settlement. | ||
inbox.cancel Cancel or deactivate an inbox lifecycle without deleting the domain taxonomy around it. | GET /api/agentic-api/domains/email/capabilities/inbox-cancelRead the capability contract, current lifecycle status, and machine-readable metadata for this email capability. | Free |
POST /api/agentic-api/domains/email/capabilities/inbox-cancel/recommendAsk AgentRouter to compare eligible routes inside this capability and return the best recommendation before execution. | Free | |
POST /api/agentic-api/domains/email/capabilities/inbox-cancel/executeExecute this capability through the selected route while AgentRouter handles pricing, wallet debits, and upstream settlement. | ||
inbox.messages.list List stored messages for an inbox so agents can browse recent inbound mail. | GET /api/agentic-api/domains/email/capabilities/inbox-messages-listRead the capability contract, current lifecycle status, and machine-readable metadata for this email capability. | Free |
POST /api/agentic-api/domains/email/capabilities/inbox-messages-list/recommendAsk AgentRouter to compare eligible routes inside this capability and return the best recommendation before execution. | Free | |
POST /api/agentic-api/domains/email/capabilities/inbox-messages-list/executeExecute this capability through the selected route while AgentRouter handles pricing, wallet debits, and upstream settlement. 1 route in this breakdown are temporarily unavailable. | ||
inbox.messages.read Read a specific stored inbound message with structured content and metadata. | GET /api/agentic-api/domains/email/capabilities/inbox-messages-readRead the capability contract, current lifecycle status, and machine-readable metadata for this email capability. | Free |
POST /api/agentic-api/domains/email/capabilities/inbox-messages-read/recommendAsk AgentRouter to compare eligible routes inside this capability and return the best recommendation before execution. | Free | |
POST /api/agentic-api/domains/email/capabilities/inbox-messages-read/executeExecute this capability through the selected route while AgentRouter handles pricing, wallet debits, and upstream settlement. | ||
inbox.messages.delete Delete a stored inbound message from an inbox-backed mailbox. | GET /api/agentic-api/domains/email/capabilities/inbox-messages-deleteRead the capability contract, current lifecycle status, and machine-readable metadata for this email capability. | Free |
POST /api/agentic-api/domains/email/capabilities/inbox-messages-delete/recommendAsk AgentRouter to compare eligible routes inside this capability and return the best recommendation before execution. | Free | |
POST /api/agentic-api/domains/email/capabilities/inbox-messages-delete/executeExecute this capability through the selected route while AgentRouter handles pricing, wallet debits, and upstream settlement. | ||
subdomain.buy Buy or create a provider-managed email subdomain for branded outbound sending. | GET /api/agentic-api/domains/email/capabilities/subdomain-buyRead the capability contract, current lifecycle status, and machine-readable metadata for this email capability. | Free |
POST /api/agentic-api/domains/email/capabilities/subdomain-buy/recommendAsk AgentRouter to compare eligible routes inside this capability and return the best recommendation before execution. | Free | |
POST /api/agentic-api/domains/email/capabilities/subdomain-buy/executeExecute this capability through the selected route while AgentRouter handles pricing, wallet debits, and upstream settlement. | ||
subdomain.status Inspect subdomain readiness, status, and operational health. | GET /api/agentic-api/domains/email/capabilities/subdomain-statusRead the capability contract, current lifecycle status, and machine-readable metadata for this email capability. | Free |
POST /api/agentic-api/domains/email/capabilities/subdomain-status/recommendAsk AgentRouter to compare eligible routes inside this capability and return the best recommendation before execution. | Free | |
POST /api/agentic-api/domains/email/capabilities/subdomain-status/executeExecute this capability through the selected route while AgentRouter handles pricing, wallet debits, and upstream settlement. | ||
subdomain.update Update subdomain configuration, policies, or other mutable sending settings. | GET /api/agentic-api/domains/email/capabilities/subdomain-updateRead the capability contract, current lifecycle status, and machine-readable metadata for this email capability. | Free |
POST /api/agentic-api/domains/email/capabilities/subdomain-update/recommendAsk AgentRouter to compare eligible routes inside this capability and return the best recommendation before execution. | Free | |
POST /api/agentic-api/domains/email/capabilities/subdomain-update/executeExecute this capability through the selected route while AgentRouter handles pricing, wallet debits, and upstream settlement. | ||
subdomain.send Send outbound mail through a purchased or configured email subdomain route. | GET /api/agentic-api/domains/email/capabilities/subdomain-sendRead the capability contract, current lifecycle status, and machine-readable metadata for this email capability. | Free |
POST /api/agentic-api/domains/email/capabilities/subdomain-send/recommendAsk AgentRouter to compare eligible routes inside this capability and return the best recommendation before execution. | Free | |
POST /api/agentic-api/domains/email/capabilities/subdomain-send/executeExecute this capability through the selected route while AgentRouter handles pricing, wallet debits, and upstream settlement. | ||
subdomain.signers.list List signer identities or permitted sending principals for a managed subdomain. | GET /api/agentic-api/domains/email/capabilities/subdomain-signers-listRead the capability contract, current lifecycle status, and machine-readable metadata for this email capability. | Free |
POST /api/agentic-api/domains/email/capabilities/subdomain-signers-list/recommendAsk AgentRouter to compare eligible routes inside this capability and return the best recommendation before execution. | Free | |
POST /api/agentic-api/domains/email/capabilities/subdomain-signers-list/executeExecute this capability through the selected route while AgentRouter handles pricing, wallet debits, and upstream settlement. | ||
subdomain.signers.create Create or register a signer identity for sending through a subdomain route. | GET /api/agentic-api/domains/email/capabilities/subdomain-signers-createRead the capability contract, current lifecycle status, and machine-readable metadata for this email capability. | Free |
POST /api/agentic-api/domains/email/capabilities/subdomain-signers-create/recommendAsk AgentRouter to compare eligible routes inside this capability and return the best recommendation before execution. | Free | |
POST /api/agentic-api/domains/email/capabilities/subdomain-signers-create/executeExecute this capability through the selected route while AgentRouter handles pricing, wallet debits, and upstream settlement. | ||
subdomain.signers.delete Revoke or delete a signer identity from a managed subdomain. | GET /api/agentic-api/domains/email/capabilities/subdomain-signers-deleteRead the capability contract, current lifecycle status, and machine-readable metadata for this email capability. | Free |
POST /api/agentic-api/domains/email/capabilities/subdomain-signers-delete/recommendAsk AgentRouter to compare eligible routes inside this capability and return the best recommendation before execution. | Free | |
POST /api/agentic-api/domains/email/capabilities/subdomain-signers-delete/executeExecute this capability through the selected route while AgentRouter handles pricing, wallet debits, and upstream settlement. | ||
subdomain.inbox.create Create an inbox underneath a managed subdomain namespace. | GET /api/agentic-api/domains/email/capabilities/subdomain-inbox-createRead the capability contract, current lifecycle status, and machine-readable metadata for this email capability. | Free |
POST /api/agentic-api/domains/email/capabilities/subdomain-inbox-create/recommendAsk AgentRouter to compare eligible routes inside this capability and return the best recommendation before execution. | Free | |
POST /api/agentic-api/domains/email/capabilities/subdomain-inbox-create/executeExecute this capability through the selected route while AgentRouter handles pricing, wallet debits, and upstream settlement. | ||
subdomain.inbox.list List inboxes that live under a managed email subdomain. | GET /api/agentic-api/domains/email/capabilities/subdomain-inbox-listRead the capability contract, current lifecycle status, and machine-readable metadata for this email capability. | Free |
POST /api/agentic-api/domains/email/capabilities/subdomain-inbox-list/recommendAsk AgentRouter to compare eligible routes inside this capability and return the best recommendation before execution. | Free | |
POST /api/agentic-api/domains/email/capabilities/subdomain-inbox-list/executeExecute this capability through the selected route while AgentRouter handles pricing, wallet debits, and upstream settlement. | ||
subdomain.inbox.update Update a subdomain-scoped inbox and its mutable configuration. | GET /api/agentic-api/domains/email/capabilities/subdomain-inbox-updateRead the capability contract, current lifecycle status, and machine-readable metadata for this email capability. | Free |
POST /api/agentic-api/domains/email/capabilities/subdomain-inbox-update/recommendAsk AgentRouter to compare eligible routes inside this capability and return the best recommendation before execution. | Free | |
POST /api/agentic-api/domains/email/capabilities/subdomain-inbox-update/executeExecute this capability through the selected route while AgentRouter handles pricing, wallet debits, and upstream settlement. | ||
subdomain.inbox.delete Delete a subdomain-scoped inbox when it is no longer needed. | GET /api/agentic-api/domains/email/capabilities/subdomain-inbox-deleteRead the capability contract, current lifecycle status, and machine-readable metadata for this email capability. | Free |
POST /api/agentic-api/domains/email/capabilities/subdomain-inbox-delete/recommendAsk AgentRouter to compare eligible routes inside this capability and return the best recommendation before execution. | Free | |
POST /api/agentic-api/domains/email/capabilities/subdomain-inbox-delete/executeExecute this capability through the selected route while AgentRouter handles pricing, wallet debits, and upstream settlement. | ||
subdomain.inbox.messages.list List stored messages from an inbox that belongs to a managed subdomain. | GET /api/agentic-api/domains/email/capabilities/subdomain-inbox-messages-listRead the capability contract, current lifecycle status, and machine-readable metadata for this email capability. | Free |
POST /api/agentic-api/domains/email/capabilities/subdomain-inbox-messages-list/recommendAsk AgentRouter to compare eligible routes inside this capability and return the best recommendation before execution. | Free | |
POST /api/agentic-api/domains/email/capabilities/subdomain-inbox-messages-list/executeExecute this capability through the selected route while AgentRouter handles pricing, wallet debits, and upstream settlement. | ||
subdomain.inbox.messages.read Read a stored message from a subdomain-scoped inbox. | GET /api/agentic-api/domains/email/capabilities/subdomain-inbox-messages-readRead the capability contract, current lifecycle status, and machine-readable metadata for this email capability. | Free |
POST /api/agentic-api/domains/email/capabilities/subdomain-inbox-messages-read/recommendAsk AgentRouter to compare eligible routes inside this capability and return the best recommendation before execution. | Free | |
POST /api/agentic-api/domains/email/capabilities/subdomain-inbox-messages-read/executeExecute this capability through the selected route while AgentRouter handles pricing, wallet debits, and upstream settlement. | ||
subdomain.inbox.messages.delete Delete a stored message from a subdomain-scoped inbox. | GET /api/agentic-api/domains/email/capabilities/subdomain-inbox-messages-deleteRead the capability contract, current lifecycle status, and machine-readable metadata for this email capability. | Free |
POST /api/agentic-api/domains/email/capabilities/subdomain-inbox-messages-delete/recommendAsk AgentRouter to compare eligible routes inside this capability and return the best recommendation before execution. | Free | |
POST /api/agentic-api/domains/email/capabilities/subdomain-inbox-messages-delete/executeExecute this capability through the selected route while AgentRouter handles pricing, wallet debits, and upstream settlement. |
Related Pages
Provision a managed inbox the agent can own, forward, inspect, and reuse later for lower-cost sending.
Inkbox
Direct
StableEmail
AgentCash
AgentMail
Direct
Persistent agent identities and inbox-backed workflows
Coverage: 1 capabilities · 4 live routes
Start with Inbox Acquire
Inspect inbox status, list retained messages, read replies, and delete processed messages through one surface.
AgentMail
Direct
AgentMail
MPP
Inkbox
Direct
Inbox monitoring, triage, and agent reply loops
Coverage: 4 capabilities · 14 live routes
Extend inbox lifetime without reprovisioning the mailbox or changing the agent address.
StableEmail
AgentCash
Long-running agents that need durable inbox ownership
Coverage: 1 capabilities · 3 live routes
Start with Inbox Topup
Provision a managed sending namespace, monitor readiness, and send from branded agent addresses.
StableEmail
AgentCash
Branded senders, multi-agent teams, and domain-based trust
Coverage: 3 capabilities · 3 live routes
Manage child inboxes and their message history under one branded namespace for specialized agent roles.
StableEmail
AgentCash
Sales agents, support agents, and role-specific branded inboxes
Coverage: 5 capabilities · 5 live routes
Modes: Managed
| 0 credits ($0) |
| Direct, MPP |
Inkbox Best when the agent needs a mailbox it can provision, inspect, update, and send from through one provider surface. 9 live routes | Managed inbox ownership plus inbound mailbox operations | Send, Inbox Acquire, Inbox Status, Inbox Update +4 more Modes: Managed | 0 credits ($0) | Direct |
Resend Strong fit when the agent only needs to send email immediately through a direct managed route. 1 live routes | Managed outbound send with fast setup | Send Modes: Managed | 10 credits ($0.01) | Direct |
SendGrid Useful as a second direct managed send route when you want another mainstream delivery option. 1 live routes | Outbound send with alternate provider coverage | Send Modes: Managed | 12 credits ($0.012) | Direct |