| Emails | Single sends and batches of up to 100, retrieve and list with newest-first cursor pagination, schedule, reschedule, cancel, html, text, templates, CC, BCC, reply-to, tags, idempotent replay and rejection of reuse with a changed payload |
| Delivery | Queued, scheduled, sent, delivered, delayed, bounced, complained, opened, clicked and suppressed, moved by advancing |
| Domains | Create, retrieve, list, update, delete, simulated SPF and DKIM records, region and tracking settings, refusal of sends from an unverified custom domain, and asynchronous verification that completes on advance |
| API keys | Create, list, rename, revoke, full-access and sending-only permissions, bearer authentication, the required User-Agent header, and missing, invalid, restricted, revoked and rate-limited credentials |
| Contacts and segments | Contacts by id or email, names, subscription state, properties, topics, segment membership, segment CRUD, and the deprecated audiences API |
| Broadcasts | Draft CRUD, audience or segment targeting, immediate or scheduled sends, cancellation, and materialization into emails on advance |