In Spotler Mail+, the External ID option is used to link contacts to a unique identifier from an external system. This determines how contacts are recognized during import and either prevents or creates duplicates, depending on how the setup is configured.
What does linking with an external ID mean?
Linking with an external ID means that a unique field from an external system is used to identify contacts.
An external ID can be a customer number or membership number. This field ensures that contacts are recognized, even when multiple contacts share the same email address.
This method is commonly used when Spotler Mail+ is connected to a CRM, ESP, or webshop system.
During the import process, you will see the following screen where you can configure the external ID:
Be careful when using an external ID
An external ID determines how contacts are recognized during a subsequent import or update. Setting or changing the external ID does not automatically update existing contacts. If the external ID is not provided consistently afterwards, new imports or updates may create duplicate contacts. These are not merged automatically.
Which topics are covered?
On this page, the following topics are covered:
- What action should I take?
- When do you deduplicate based on email address?
- When do you deduplicate based on external ID?
- Frequently asked questions
What action should I take?
The correct action depends on the import file and the chosen deduplication strategy.
Deduplicating based on email address
Skip the external ID step when deduplicating based on email address.
Leave the setting as Not linked and continue to the next step. Make sure the email address is correctly mapped to the appropriate database field.
Deduplicating based on external ID
Use an external ID when you do not want to deduplicate based on email address.
Select the field that contains the unique identifier, such as a customer number. This field is used to recognize and update existing contacts.
When do you deduplicate based on email address?
With this method, the email address is the unique identifier of a contact.
This means an email address can only exist once in the database, preventing multiple emails from being sent to the same address.
Advantage: less error-prone and prevents duplicate sends.
Disadvantage: multiple individuals using the same email address are treated as one contact.
When do you deduplicate based on external ID?
Deduplicating based on external ID is suitable when contacts must remain unique, even if they share the same email address.
This is relevant for example in households or organizations where multiple individuals use one email address.
Advantage: aligns with external systems and enables individual communication.
Disadvantage: the same email address may receive multiple emails if not handled carefully.
Frequently asked questions
An external ID is only required when linking contacts to an external system or when an email address is not sufficient as a unique identifier.
If the external ID does not match existing data, the software cannot identify the contact and will create a new record. This may result in duplicates.
It is technically possible to adjust deduplication rules for a specific situation. This may seem useful, but it can have lasting effects on your database.
If deduplication rules are temporarily relaxed or disabled, duplicate contacts may be created.
These duplicates are not automatically merged afterwards. The duplicate records will remain in the database.
This can result in multiple emails being sent to the same person, incorrect unsubscribe handling, and additional manual cleanup work.
Only adjust deduplication rules when necessary and always assess the impact beforehand.
What is the result?
By correctly linking an external ID, contacts are consistently recognized, the database remains reliable, and unwanted duplicates or data loss are prevented.