Here you can find a list of the terms that we use in the Emarsys application interface and in the supporting documentation.


Term Description
Contacts They are your customers, the potential recipients of your emails.
External ID (same as external key) External IDs are used to identify a contact in your database. To be able to map customers between an external database and Emarsys application , the external ID is also stored in the Emarsys application. In case “external ID” is a real ID in your database, meaning that it does not correspond to any of the system fields in the Emarsys application, then a custom field has to be created for the external ID. This field should be called externalId (please note the capitalization), since many of the third-party applications with which Emarsys integrates look specifically for a field with this name.
Field A property (i.e. key-value pair) of the contact. A field could be a System field, predefined by the Emarsys application, or a Custom field, defined by you.
Field ID Since all fields are key-value-pairs, we need a key. Field IDs are the keys which allow you to get all fields via the API. You can find a full list the system field IDs here.The Emarsys API works only with Field IDs and ignores field names. That means that if you delete a field and then recreate it with the same name, it will be given a new ID, and you will have to update any existing API calls accordingly.
Key The field that is used to identify the contact in the Emarsys application. By default, this is the email address with field ID ‘3’. Note: Key is used for duplication handling. The External ID and key can be the same, but don’t have to be.
Source This field in the Emarsys application indicates how and where a contact was created in your system. You can use it to export all registrations from a particular source, for example, or to compare two sources.


Term Description
Batch email An email sent to a group of contacts, which is defined by a segment or a contact list.
Email The content you want to send to your recipients. You can create emails using the Emarsys application UI, but also via the API. Since the API does not allow you to use all features (e.g. templates), it is easiest if you use the API to trigger emails created in the Emarsys application UI.
External event This is a named event that triggers an email to be sent. External events always include references to the contact the email will be sent to. Therefore, you can use external events to send transactional emails.
Program A program is a series of actions, starting from an entry point (ie. a trigger) and progressing along a decision tree until an end point. There are different types of programs. From the API you can trigger transactional programs.
Transactional email An email triggered by an external event. It is sent to the contact included in the external event.

Contact list-related

Term Description
Contact List A static group of contacts. After its definition, the list will not change, unless you change it intentionally. Contact lists can be created by saving imported contacts into a contact list, using the API or saving a segment into a contact list to make it static.
Segment A dynamically generated group of contacts. A segment is generated by a filter. Each time the segment is used the filter runs and the segment’s contacts are updated.