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.
How deliverability compliance & bounce rules behaves.
Answers about the execution flow, failure handling and limits of this module.
Do you support one-click unsubscribe?
Yes. Every campaign includes an RFC 8058 List-Unsubscribe-Post header, which Gmail and Yahoo now require from bulk senders. A recipient can opt out in one action without leaving their inbox.
How are unsubscribes and bounces handled?
Both are added to a workspace-wide suppression list and excluded from every future campaign automatically. Entries are stored as SHA-256 hashes, so opt-outs are honoured without retaining a readable copy of the address of someone who asked not to be contacted.
What is the difference between a soft and a hard bounce here?
A hard bounce means the address does not exist and is suppressed permanently — whether the receiving server rejected it during sending or returned a delivery failure report afterwards. A soft bounce is a temporary failure such as a full mailbox, and is retried on a backoff schedule rather than suppressed, so a real contact is not lost to a passing problem.
Why would I use a custom tracking domain?
Tracking links on a shared domain inherit the reputation of everyone else using it. A custom CNAME tracking domain means your open and click links resolve on your own subdomain, keeping that reputation isolated to you.