When connecting Salesmachine to sendgrid , additional setup needs to be done.
To do so,
Click on this link : https://app.sendgrid.com/settings/mail_settings
Select section "Event Notification"
Then, copy past results in the url domain
https://api.salesmachine.io/v1/hook?srvc=sendgrid&api_token=<api_token>Replace the <api_token> with the token found in Salesmachine API Section : https://my.salesmachine.io/app/api/edit