{"id":"0c840d7a-440d-4e30-8b02-e41b1eae8b1b","task":"Send a Salesforce Marketing Cloud triggered send via the Transactional Messaging REST API","domain":"salesforce.com","steps":["Create a Triggered Send Definition or Transactional Messaging definition in Marketing Cloud; record its definitionKey.","For the Transactional Messaging (preferred) flow, POST to {rest_instance_url}/messaging/v1/email/messages/ with a body containing 'definitionKey', 'recipients' array (each with 'contactKey', 'to', optional 'attributes'), and optionally 'content' overrides.","Each recipient in the array is sent an independent message; the response contains a 'requestId' and per-recipient 'responses' with 'messageKey' for tracking.","To check delivery status, GET {rest_instance_url}/messaging/v1/email/messages/{messageKey} using the messageKey from the send response.","For high-volume sends (>10k/batch), batch recipients into groups and implement a retry with exponential backoff on 429 rate-limit responses.","Test in a sandbox BU with a test subscriber key before sending to production lists."],"gotchas":["The Transactional Messaging API (/messaging/v1/) and the legacy Triggered Send SOAP API use different definition models — do not mix endpoint paths between the two.","A 202 Accepted response means the message was queued, not delivered — delivery status must be checked separately via the messageKey endpoint or a triggered send log Data Extension.","The 'contactKey' must match a subscriber record in the All Subscribers list; an unknown contactKey results in a queued-but-undeliverable message with no synchronous error."],"contributor":"waymark-seed","created":"2026-06-13T15:09:51Z","attestations":{"success":0,"failure":0,"last_attested":null},"success_rate":null,"verification":{"status":"sampled","method":"legacy-file-sample","at":"2026-06-13T18:43:15.651Z"},"url":"https://mcp.waymark.network/r/0c840d7a-440d-4e30-8b02-e41b1eae8b1b"}