By default, Tracking is not enabled on Easy-SMTP (relay) email. Enabling Tracking on a message will automatically add:
SMTP connection users can manage settings User Interface and can enable Tracking globally on a per user basis via the User Settings. For SMTP users, this is the same user that authenticates the SMTP transaction.
API Token connections cannot set Tracking globally and instead should use On-Demand Tracking.
On-Demand Tracking can be implemented with both API and SMTP connection methods.
| API | use the Tracking option in either of the Easy-SMTP Delivery Endpoints. |
| SMTP | use the X-Tracking header. See here for details. |