Message Delivery Model

This section explains how messages are submitted, processed, and delivered by the platform.

It describes the technical delivery mechanism used by the Delivery API.

Deliveries and Envelopes

A delivery consists of one or more envelopes. Each envelope refers to a message body file and optionally one or more attachments.

An envelope defines:

• Sender
• Recipients
• Message Body
• Attachments
• Features

Envelopes submitted via the REST API are processed as a single set, whereas file-based deliveries process envelopes in batches.

The platform guarantees atomic delivery per envelope.

All recipients receive the message, or none do.

Partial delivery is not possible.

Message content can be submitted directly through the Delivery API using REST.

In this model, the sender includes:

• Envelope metadata
• Message body
• Attachments, when applicable

The content is transmitted to the platform as part of the API request.

The platform performs initial validation at submission time. Once accepted, the envelope enters the standard ingestion and processing pipeline.

This method is typically used when:

• The sender prefers direct API integration
• Message sizes are within supported limits
• External storage is not required

After submission, processing is identical to all other delivery types.

Message content can be submitted using S3 compatible storage.

In this model, the sender:

• Uploads message body and attachments to S3 compatible storage
• Submits envelope metadata via the Delivery API
• Provides access credentials for the platform to retrieve the content

The platform retrieves the content during ingestion and performs validation before processing.

This method is typically used when:

• Message sizes are large
• File transfer must be handled outside the API request
• Storage separation is required by the sender

After retrieval, processing is identical to all other delivery types.

Before processing, the platform validates:

• Envelope structure
• File presence
• Encryption parameters
• Hash values

Invalid content results in failed deliveries.

During ingestion, the platform:

1. Scans content
2. Decrypts when required
3. Encrypts per recipient
4. Stores content securely

Recipients are resolved and verified before delivery.

Subscription and access rules are enforced.

The platform enforces features such as:

• Scheduled delivery
• Interim repository
• Open receipts

Each envelope results in:

• Delivered
• Rejected
• Failed

Results are available in delivery reports.