Properties
| Name | Type | Description |
|---|---|---|
| attachments | array | Attachments to send with the message. |
| bcc | array | Hidden copied recipients. |
| cc | array | Visible copied recipients. |
| custom_headers | object | Custom X-* headers to include. Mailbox writes reject X-SES-TENANT, X-SES-CONFIGURATION-SET and X-SES-MESSAGE-TAGS case-insensitively. |
| from | object | |
| html_body | string | HTML body. |
| reply_to | array | Reply-To recipients. |
| subject | string | Subject line; defaults to empty. |
| text_body | string | Plain text body. |
| to | array | Primary recipients. Supply 1 to 50 recipients in total across To, Cc and Bcc. |
JSON Schema
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"$id": "https://artifacts.apis.io/sendmux-ai/json-schema/sendmux-ai-send-mailbox-message-body-schema.json",
"title": "SendMailboxMessageBody",
"x-generated": "2026-10-31",
"x-method": "derived",
"x-generator": "derive-json-schema.py",
"x-source": "openapi/openapi-app.json#/components/schemas/SendMailboxMessageBody",
"additionalProperties": false,
"properties": {
"attachments": {
"description": "Attachments to send with the message.",
"items": {
"anyOf": [
{
"additionalProperties": false,
"properties": {
"content": {
"description": "Base64-encoded content for small inline attachments. Use /mailbox/attachments:upload for larger files.",
"type": "string"
},
"content_type": {
"type": "string"
},
"filename": {
"type": "string"
}
},
"required": [
"filename",
"content_type",
"content"
],
"type": "object"
},
{
"additionalProperties": false,
"properties": {
"blob_id": {
"description": "Blob ID returned by /mailbox/attachments:upload.",
"type": "string"
},
"content_type": {
"type": "string"
},
"filename": {
"type": "string"
}
},
"required": [
"filename",
"content_type",
"blob_id"
],
"type": "object"
}
]
},
"type": "array"
},
"bcc": {
"description": "Hidden copied recipients.",
"items": {
"$ref": "#/$defs/MailboxAddress"
},
"maxItems": 50,
"type": "array"
},
"cc": {
"description": "Visible copied recipients.",
"items": {
"$ref": "#/$defs/MailboxAddress"
},
"maxItems": 50,
"type": "array"
},
"custom_headers": {
"additionalProperties": {
"type": "string"
},
"description": "Custom X-* headers to include. Mailbox writes reject X-SES-TENANT, X-SES-CONFIGURATION-SET and X-SES-MESSAGE-TAGS case-insensitively.",
"type": "object"
},
"from": {
"allOf": [
{
"$ref": "#/$defs/MailboxAddress"
},
{
"description": "Sender address. Defaults to mailbox identity."
}
]
},
"html_body": {
"description": "HTML body.",
"type": "string"
},
"reply_to": {
"description": "Reply-To recipients.",
"items": {
"$ref": "#/$defs/MailboxAddress"
},
"type": "array"
},
"subject": {
"description": "Subject line; defaults to empty.",
"maxLength": 998,
"type": "string"
},
"text_body": {
"description": "Plain text body.",
"type": "string"
},
"to": {
"description": "Primary recipients. Supply 1 to 50 recipients in total across To, Cc and Bcc.",
"items": {
"$ref": "#/$defs/MailboxAddress"
},
"maxItems": 50,
"type": "array"
}
},
"type": "object",
"$defs": {
"MailboxAddress": {
"additionalProperties": false,
"properties": {
"email": {
"format": "email",
"type": "string"
},
"name": {
"type": [
"string",
"null"
]
}
},
"required": [
"email",
"name"
],
"type": "object"
}
}
}
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