Deliverability Compliance & Bounce Rules Flow
Understand the core mechanics, queues, and logic routines running on our servers when processing this module.
System Execution Pipeline
Below is the step-by-step sequence of events executed by our background workers.
Header Injection
During mail assembly, workers append the RFC 8058 List-Unsubscribe header.
Recipient Action
Recipient clicks Unsubscribe in Gmail/Outlook. The client sends a POST request to our server.
Suppression Hash
The recipient's email is hashed with SHA-256 and added to the Suppression List.
Queue Cleanup
Workers scan BullMQ and delete any pending jobs matching the suppressed address.
Bounces
Receiving server errors are evaluated. Hard bounces update the suppression list, and soft bounces are scheduled for retries.
Developer & Architect Notes
Technical Architecture
This module operates as a stateless service hosted across horizontally scalable server nodes. Distributed state coordinates through highly optimized Redis transactions to ensure consistency without deadlocks.
Edge Fail-Safe Rules
Critical protocols (like connection failure retries, cool-down timers, and data limits) are verified before outbound dispatches. Failures degrade gracefully, prioritizing list health and preventing blacklisting.