For added security, we have added functionality to validate that email tracking URL hash codes originate from the same domain in the subscription. A unique email tracking URL hash code is what is used to identify which Marketo instance the link is coming from, enabling the tracking functionality in your emails.
Here’s an example of how an email tracking URL is constructed:
Enhancement being made:
This enhancement will add extra validation to the tracking URLs used in your emails.
When our tracking server receives the link, it will use the URL hash code to identify the Marketo instance. It then looks up the branding domains associated with the subscription.
If the domain presented in the URL matches a branding domain we have listed for you, the link will connect just as it should. If the domain in the URL does not match a domain in our database, it will be considered suspicious and will be stopped and a "404 error" will be displayed.