Update collection to reflect API docs changes (Aug 2025 – Apr 2026)

[Keith-wright]

Summary

Syncs the Postman collection with all API documentation changes made since PR #9.

Changes included:

• Usage — New GET /api/v1/usage endpoint added
• Transmissions — New override field example added (Create a Transmission (stored template, inline recips, override))
• SMTP — Sandbox section removed (docs PR #567)
• Suppression List — Added list_id query param support on Search and Delete endpoints; fixed List All Scheduled Transmissions which had campaign_id/template_id incorrectly set as headers instead of query params
• Sending Domains / DKIM Keys — New suite of DKIM key management endpoints: Get DKIM Keys, Create a DKIM Key, Update a DKIM Key, Delete a DKIM Key
• Tracking Domains — New managed HTTPS parameters: certificate_status, is_managed_certificate, redirect_to_https; new Update Managed Certificate endpoint
• Metrics — New endpoints: Deliverability Metrics by Subject Campaign, Deliverability Metrics by Mailbox Provider, Deliverability Metrics by Mailbox Provider Region, Mailbox Providers List, Mailbox Provider Regions List, Subject Campaigns List, Templates List, Sending Domains List, Advanced Query JSON Schema

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Note

Low Risk
Low risk documentation/artifact update: modifies only the Postman collection JSON, with no runtime code changes; main risk is incorrect endpoint examples/params confusing consumers.

Overview
Syncs sparkpost-api Postman collection with newer API docs by adding new request groups/endpoints (notably GET /api/v1/usage, expanded Metrics deliverability endpoints + filter/list endpoints, DKIM key management under Sending Domains, suppression list summary and single-recipient upsert, and tracking-domain managed certificate actions).

Also fixes/reshapes existing requests to match docs: updates deliverability metric routes/params, adds/clarifies list_id scoping behavior on suppression operations, corrects transmissions list filtering to use query params, adds a transmission override example, and expands sending-domain request coverage (search params + CRUD/verify).

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