---
id: ADR-PFM-NOT-020
title: Purpose-Classified Lanes Keep Transactional Mail Ahead of Bulk Mail
product_area: platform
module: notifications
revision: 1
status: proposed
design_intent: proposed
source_sha:
  services-platform: ad3f6a6582843008ed0f5a17b131878d15829af1
  react-console: baf6dae382d6f41dce976c7f848667ccc37e076f
decision: Purpose classification selects two delivery lanes, reserving forty percent for transactional
  mail with borrowing and limiting Marketing to sixty percent plus a quota brake.
constrains:
- DOM-PFM-NOT-005
- SVC-PFM-NOT-communications
- WF-PFM-NOT-012
- WF-PFM-NOT-010
- STATE-PFM-NOT-015
origin: FND-PFM-NOT-012 (the Marketing lane has no matching Andrew decision in the examined records);
  services-platform:docs/communications/architecture.md#21. The marketing lane (MKT-M1, 2026-10-21)
alternatives:
- option: One queue for all mail
  why_not: One backlog could delay urgent mail behind bulk campaigns.
- option: Per-workspace fair shares now
  why_not: Workspace fairness requires the open allocation policy rather than an implementation assumption.
consequences:
- Marketing requests supply subscription and unsubscribe information.
- Capacity waits create delayed work without spending the provider retry budget.
- Current lane allocation does not guarantee fairness among workspaces.
supersedes: []
evidence:
- 'services-platform at ad3f6a65: modules/communications/services/dispatch/{lanes,lane-budget,lane-bucket,quota-guard}.ts.'
---
# Purpose-Classified Lanes Keep Transactional Mail Ahead of Bulk Mail

## Context

Transactional and bulk mail share account capacity but have different urgency.

## Decision

Purpose classification selects two delivery lanes, reserving forty percent for transactional mail with borrowing and limiting Marketing to sixty percent plus a quota brake.

## Alternatives Considered

One backlog could delay urgent mail behind bulk campaigns. Workspace fairness requires the open allocation policy rather than an implementation assumption.

## Consequences

Marketing requests supply subscription and unsubscribe information. Capacity waits create delayed work without spending the provider retry budget. Current lane allocation does not guarantee fairness among workspaces.