I'm new to Salesforce and I've been trying to use the messageDefinitionSends endpoint to send a single email message. I started by creating an email message, a data extension and a triggered send. I saved, published and started the triggered send.

Then, using Postman, I requested an access token via https://myorgsubdomain.auth.marketingcloudapis.com/v2/token and got the following:

    "access_token": "sometoken",
    "token_type": "Bearer",
    "expires_in": 1079,
    "scope": "email_read email_send email_write ...", (and others, removed for simplicity)
    "soap_instance_url": "https://myorgsubdomain.soap.marketingcloudapis.com/",
    "rest_instance_url": "https://myorgsubdomain.rest.marketingcloudapis.com/"

Then, I copied the token and used in the following request

POST /messaging/v1/messageDefinitionSends/key:123456/send HTTP/1.1
Host: myorgsubdomain.rest.marketingcloudapis.com
Content-Type: application/json
Authorization: Bearer sometoken

    "To": {
        "Address": "me@my.org",
        "SubscriberKey": "me@my.org"
    "Options": {
        "RequestType": "ASYNC"

where 123456 is the external key for the triggered send I created previously. The recipient SubscriberKey equals the destination email address for this specific case (I confirmed via the SOAP API). When I POST the request I receive an empty response body with the HTTP response 404. I've also tried using the endpoint https://www.exacttargetapis.com/messaging/v1/messageDefinitionSends/key:123456/send but I either receive a 404 or 401 response.

I'm struggling with this issue for a while now and I have no idea what might be wrong. Any suggestions?


  • I would verify the key/id of your Triggered Send Definition. The only time I receive a 404 is when this is incorrect. Aug 9, 2019 at 12:50
  • @Gortonington I've checked the external key of the Triggered Send Definition countless times. I've even tried changing it a few times (I paused, edited, published and restarted the Definition) and the result is still the same. It matches the one I see in the column "External Key".
    – pbucho
    Aug 9, 2019 at 13:29
  • Is the token you are using associated with the same BU as your TSD? Sorry for the dumb questions, I just feel that without some platform issue (require SFMC support), that something small is likely to be the culprit of your error. Aug 9, 2019 at 13:57
  • I believe so. I only have access to the Marketing Cloud interface, and the people who provided me with the client ID and secret said it was for my BU. I confirmed that the subdomain for the authentication matched the one they sent me, and the authentication request has always been successful. I've tried a SOAP request using the same token to get a SubscriberKey and it returned a valid response.
    – pbucho
    Aug 9, 2019 at 14:48
  • have you tried a retrieve or execute to the Triggered Send Object in SOAP to verify if it is the endpoint or not? Aug 9, 2019 at 19:08

1 Answer 1


As per EazyE's comment, I needed to add the parameter account_id to the token request, using as value the MID of my Business Unit. Then, I used the token in the messageDefinitionSends/send method and the response returned was Queued and I checked that the TSD had a message in queue.


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