If a prospect is deleted, they are moved to the Recycle Bin (under Administration). The prospect record may be restored manually by clicking Undelete in the Recycle Bin or automatically in a couple of different ways.
What happens if a deleted prospect submits a form?
If your account does not allow multiple prospects with the same email address:
If the deleted prospect reconverts by filling out a form with the same email address that was associated with their record before, the record will be undeleted from the Recycle Bin and will appear again in the prospects table. The record will also be undeleted if a user manually creates a new prospect with the same email address.
If your account does allow multiple prospects with the same email address:
If the deleted prospect reconverts by filling out a form with the same email address that was associated with a record before, Pardot will attribute the activity to the prospect record with the most recent Last Activity field. If the record with the most recent last activity field is in the recycle bin, it will be undeleted and the record will appear again in the prospects table.
What happens if a deleted prospect is reimported?
If the deleted prospect is imported into Pardot with the same email address or CRM ID that is associated with their existing record, you have the option to undelete the record from the Recycle Bin so it appears in the Prospects List again. The "Un-delete matching prospects found in the recycle bin during this import" option is on step 4 of the Import wizard. If you want to leave the prospects in the Recycle bin, do not check this option.
For more about deleted prospects in other scenarios, see this article.