X-AbuseHQ-Resolve:The value of the Header needs to be in this form when you decide to use contracts:
JSONand this way, when not using contracts:
JSONThe number of subscriber_keys and contract_keys is not restricted, but we recommend only adding necessary ones and keeping the values as simple as possible. The correct JSON part has to be encoded with BASE64 and added as a value to the X-Header, which will end up looking like this:
Adding a header like this to all outbound emails will let AbuseHQ automatically do all the magic for you and will present you with the correct Contract and Subscriber information.