email_engine — Email Campaign Delivery

The email engine sends one approved campaign to its approved segment. It resolves recipients in keyset batches, skips missing-email and suppressed profiles, renders templates, dispatches through the configured adapter, and writes idempotent cdp_campaign_dispatch_logs records. Each recipient is isolated with a database savepoint so one failure does not abort the batch.

Dagster interface

• Job: email_engine_job

• Op: send_campaign_op

• Run config:

  ops:
    send_campaign_op:
      config:
        campaign_id: "<uuid>"
        tenant_id: "<uuid>"

The implementation is in email_engine/send.py. The job is normally submitted by campaign_activation_job, but can also be triggered directly by the API’s Dagster client.

Package layout

Path	Responsibility
dagster_defs.py	Dagster job and typed op configuration
email_engine/send.py	Campaign validation, recipient batching, rendering, dispatch, and ledger writes
email_engine/adapters.py	Provider adapter selection
email_engine/connector_config.py	Tenant-scoped provider configuration
email_engine/rendering.py	Template rendering and tracking URL injection
email_engine/tracking.py	Tracking-token generation
tests/	Delivery, adapter, rendering, and Dagster tests

Local development

cd customer360-backend/email_engine
./run_tests.sh

The service uses the database, DAO, dotenv, and Dagster dependencies declared in requirements.txt.