When you remove records from a Salesforce object, they are moved to the recycle bin and are called soft deleted. Soft deleted recordings can be recovered. Whereas when you delete a permanent record from a Salesforce object, it says very corrupt. Hardly deleted records cannot be recovered.
To make sure that the Salesforce records are hard deleted from IICS, go to the Hard Delete option if you choose the Delete Action in the Target conversion. If you don’t select this option, the delete command will be treated as a soft delete.