> ## Documentation Index
> Fetch the complete documentation index at: https://aisa.one/docs/llms.txt
> Use this file to discover all available pages before exploring further.
# Send Message
> Sends a new email from one inbox and returns message_id and thread_id.
Sends a new email from one inbox and returns `message_id` and `thread_id`. Takes `to`, `cc`, `bcc`, `subject`, `text`, `html`, `labels` and `attachments`. 🔴 **This sends real email and it cannot be recalled.** Every AIsa caller shares one AgentMail account, so this reaches inboxes other callers created, so the sending address may not be one you created — check `get_agentmail_inbox` first. To answer an existing message use `post_agentmail_inbox_message_reply`; to write without sending, `post_agentmail_inbox_draft`.
## Example
```bash REST theme={null}
curl -X POST "https://api.aisa.one/apis/v1/agentmail/inboxes/{inbox_id}/messages/send" \
-H "Content-Type: application/json" \
-H "Authorization: Bearer YOUR_API_KEY"
```
```jsonc MCP theme={null}
// Copy this whole block into Claude Code, Codex, Cursor or any coding agent.
// It carries everything needed to connect, authorize and run this example —
// no key to paste, one click of Allow in the browser.
{
"operation_id": "post_agentmail_inbox_message_send",
"arguments": {},
"max_price_usd": 0.05
}
// ── for the agent ─────────────────────────────────────────────────────────
// Register the AIsa MCP server, then call its `use` tool with the JSON above.
// name aisa
// endpoint https://mcp.aisa.one/mcp
// transport streamable-http
// auth OAuth. The server publishes RFC 9728 metadata, so open a
// browser and the user clicks Allow once — nothing to paste.
// If AISA_API_KEY is set, send it as a bearer header instead.
// Use your own MCP mechanism, not a hand-edited config file:
// Codex codex mcp add aisa --url https://mcp.aisa.one/mcp
// Claude Code claude mcp add --transport http -s user aisa https://mcp.aisa.one/mcp
// Cursor / VS Code a "url" entry for https://mcp.aisa.one/mcp in the MCP config
// The server lists five tools over https://mcp.aisa.one/servers worth of APIs:
// search, get_details, use, batch_use, list_categories. search and
// get_details are free; use is billed per call and max_price_usd refuses
// anything above the cap before spending. This operation's full contract —
// every argument, the response shape, the price and the pitfalls — is at
// https://aisa.one/docs/api-reference/agentmail/post_agentmail-inboxes-inbox-id-messages-send.md
// Then run the call and show me the result.
```
**First time?** Point any MCP client at `https://mcp.aisa.one/mcp` — Claude
Code, Codex, Cursor, VS Code and the rest. Authorization is OAuth: the client
opens a browser, you click Allow once, and there is no key to paste. The
commands per client, and what each call costs, are on
[aisa.one/mcp](https://aisa.one/mcp#connect).
[Set this endpoint up in your agent →](https://aisa.one/mcp?from=/api-reference/agentmail/post_agentmail-inboxes-inbox-id-messages-send)
## OpenAPI
````yaml openapi/agentmail.json POST /agentmail/inboxes/{inbox_id}/messages/send
openapi: 3.1.0
info:
title: AgentMail API
version: 1.0.0
description: >-
AgentMail email API endpoints exposed through the AIsa unified gateway.
Adapted from the upstream docs.agentmail.to OpenAPI spec.
servers:
- url: https://api.aisa.one/apis/v1
security:
- Bearer: []
paths:
/agentmail/inboxes/{inbox_id}/messages/send:
post:
tags:
- subpackage_inboxes.subpackage_inboxes/messages
summary: Send Message
description: >-
Sends a new email from one inbox and returns `message_id` and
`thread_id`. Takes `to`, `cc`, `bcc`, `subject`, `text`, `html`,
`labels` and `attachments`. 🔴 **This sends real email and it cannot be
recalled.** Every AIsa caller shares one AgentMail account, so this
reaches inboxes other callers created, so the sending address may not be
one you created — check `get_agentmail_inbox` first. To answer an
existing message use `post_agentmail_inbox_message_reply`; to write
without sending, `post_agentmail_inbox_draft`.
operationId: post_agentmail_inbox_message_send
parameters:
- name: inbox_id
in: path
required: true
schema:
$ref: '#/components/schemas/type_inboxes_InboxId'
- name: Authorization
in: header
description: Bearer authentication
required: true
schema:
type: string
requestBody:
content:
application/json:
schema:
$ref: '#/components/schemas/type_messages_SendMessageRequest'
responses:
'200':
description: Response with status 200
content:
application/json:
schema:
$ref: '#/components/schemas/type_messages_SendMessageResponse'
'400':
description: Error response with status 400
content:
application/json:
schema:
$ref: '#/components/schemas/type__ValidationErrorResponse'
'403':
description: Error response with status 403
content:
application/json:
schema:
$ref: '#/components/schemas/type__ErrorResponse'
'404':
description: Error response with status 404
content:
application/json:
schema:
$ref: '#/components/schemas/type__ErrorResponse'
components:
schemas:
type_inboxes_InboxId:
type: string
description: The ID of the inbox.
title: InboxId
type_messages_SendMessageRequest:
type: object
properties:
labels:
$ref: '#/components/schemas/type_messages_MessageLabels'
reply_to:
$ref: '#/components/schemas/type_messages_SendMessageReplyTo'
to:
$ref: '#/components/schemas/type_messages_SendMessageTo'
cc:
$ref: '#/components/schemas/type_messages_SendMessageCc'
bcc:
$ref: '#/components/schemas/type_messages_SendMessageBcc'
subject:
$ref: '#/components/schemas/type_messages_MessageSubject'
text:
$ref: '#/components/schemas/type_messages_MessageText'
html:
$ref: '#/components/schemas/type_messages_MessageHtml'
attachments:
$ref: '#/components/schemas/type_messages_SendMessageAttachments'
headers:
$ref: '#/components/schemas/type_messages_SendMessageHeaders'
title: SendMessageRequest
type_messages_SendMessageResponse:
type: object
properties:
message_id:
$ref: '#/components/schemas/type_messages_MessageId'
thread_id:
$ref: '#/components/schemas/type_threads_ThreadId'
required:
- message_id
- thread_id
title: SendMessageResponse
type__ValidationErrorResponse:
type: object
properties:
name:
$ref: '#/components/schemas/type__ErrorName'
errors:
description: Validation errors.
required:
- name
- errors
title: ValidationErrorResponse
type__ErrorResponse:
type: object
properties:
name:
$ref: '#/components/schemas/type__ErrorName'
message:
$ref: '#/components/schemas/type__ErrorMessage'
required:
- name
- message
title: ErrorResponse
type_messages_MessageLabels:
type: array
items:
type: string
description: Labels of message.
title: MessageLabels
type_messages_SendMessageReplyTo:
$ref: '#/components/schemas/type_messages_Addresses'
description: Reply-to address or addresses.
title: SendMessageReplyTo
type_messages_SendMessageTo:
$ref: '#/components/schemas/type_messages_Addresses'
description: Recipient address or addresses.
title: SendMessageTo
type_messages_SendMessageCc:
$ref: '#/components/schemas/type_messages_Addresses'
description: CC recipient address or addresses.
title: SendMessageCc
type_messages_SendMessageBcc:
$ref: '#/components/schemas/type_messages_Addresses'
description: BCC recipient address or addresses.
title: SendMessageBcc
type_messages_MessageSubject:
type: string
description: Subject of message.
title: MessageSubject
type_messages_MessageText:
type: string
description: Plain text body of message.
title: MessageText
type_messages_MessageHtml:
type: string
description: HTML body of message.
title: MessageHtml
type_messages_SendMessageAttachments:
type: array
items:
$ref: '#/components/schemas/type_attachments_SendAttachment'
description: Attachments to include in message.
title: SendMessageAttachments
type_messages_SendMessageHeaders:
type: object
additionalProperties:
type: string
description: Headers to include in message.
title: SendMessageHeaders
type_messages_MessageId:
type: string
description: ID of message.
title: MessageId
type_threads_ThreadId:
type: string
description: ID of thread.
title: ThreadId
type__ErrorName:
type: string
description: Name of error.
title: ErrorName
type__ErrorMessage:
type: string
description: Error message.
title: ErrorMessage
type_messages_Addresses:
oneOf:
- type: string
- type: array
items:
type: string
title: Addresses
type_attachments_SendAttachment:
type: object
properties:
filename:
$ref: '#/components/schemas/type_attachments_AttachmentFilename'
content_type:
$ref: '#/components/schemas/type_attachments_AttachmentContentType'
content_disposition:
$ref: '#/components/schemas/type_attachments_AttachmentContentDisposition'
content_id:
$ref: '#/components/schemas/type_attachments_AttachmentContentId'
content:
type: string
description: Base64 encoded content of attachment.
url:
type: string
description: URL to the attachment.
title: SendAttachment
type_attachments_AttachmentFilename:
type: string
description: Filename of attachment.
title: AttachmentFilename
type_attachments_AttachmentContentType:
type: string
description: Content type of attachment.
title: AttachmentContentType
type_attachments_AttachmentContentDisposition:
type: string
enum:
- inline
- attachment
description: Content disposition of attachment.
title: AttachmentContentDisposition
type_attachments_AttachmentContentId:
type: string
description: Content ID of attachment.
title: AttachmentContentId
securitySchemes:
Bearer:
type: http
scheme: bearer
````
This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.