Sending attachments in API V3 less than 3MB via JSON

In API V3, unlike previous versions, files/attachments are not uploaded separately but are directly attached when sending a message or creating a draft. This integration simplifies workflows by allowing attachments to be part of the initial message or draft creation process.

Attachment limits are 3MB for JSON.

Note: supports in_line attachments

To send emails larger than this you will need to send them as multipart, as a developer it might be easier to simply send all emails as Content-Type: multipart/form-data .

Both of the POST /v3/grants/{grant_id}/drafts and the POST /v3/grants/{grant_id}/messages/send endpoint supports attachments field.

Attachment field structure:

"attachments": [
  {
    "content": "base64 encoded attachment",
    "content_type": "string",
    "filename": "string",
    "content_id": "string",
  }
]

Please note:  If the draft includes attachments. Must be Base64-encoded.

Resources

• Create a Draft
• Send a Message
• Add attachments to a Draft
• Attachments

Updated June 27, 2024 12:47