Hello Antonio,
you can set the status in a corresponding field during data migration (activities "Migration of Customers" and "Migration of Suppliers"), You will find this field labeled as "Status" in the migration templates on the data sheet "General". Please be aware that this column is hidden by default (Column 15 in Suppliers, column 27in Customers, enlarge line 7 to see the full field documetation in the header field)
Regards
Michael