How to lookup Oracle sales cloud to check if a contact record already exist using email and if so, then only trigger the creation of contact from Eloqua
Is this possible to do from Eloqua?
You should be able to set up data management rules on the CX Sales side: https://docs.oracle.com/en/cloud/saas/sales/21d/oasal/accounts-and-contacts.html#OASAL3424508.
If the record is created through the Eloqua program, you can store the CX Sales record ID on the Eloqua Contact. You can add a condition to the program that will check for the presence of the CRM Id before syncing data to CX Sales CRM.