Add File Attachment to Message

Adds a file attachment to a message in Microsoft 365 Outlook.

POST

Query

Field selectionChoose which fields should be included in the response. Learn more

string

Comma-separated response fields to include.

Body

Arguments

stringrequired

The draft or message ID to attach the file to.

stringrequired

Name of the file attachment.

stringrequired

MIME type of the attachment content.

stringrequired

Base64-encoded file content. Microsoft Graph supports this action for attachments under 3 MB.

Try this request

Request

curl --request POST \
  --url "https://connect.mindcloud.co/v1/universal/microsoft365Outlook/0.0.5/actions/add-file-attachment-to-message" \
  --header "Authorization: Bearer $MINDCLOUD_API_TOKEN" \
  --header "Content-Type: application/json" \
  --data '{
  "connectionId": "$CONNECTION_ID",
  "messageId": "",
  "name": "",
  "contentType": "text/plain",
  "contentBytes": ""
}'

{
  "success": true,
  "data": [
    {
      "@odata": {
        "type": "string"
      },
      "contentBytes": "string",
      "contentType": "string",
      "id": "string",
      "isInline": true,
      "lastModifiedDateTime": "2026-05-07T12:00:00.000Z",
      "name": "Ava Chen",
      "size": 1
    }
  ],
  "meta": {}
}

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