Prevent duplicates import in crm
Currently, if you install https://www.odoo.com/page/crm, you are able to go to the Kanban Board of the crm and import your leads there using lets say csv file.
How I can prevent duplicates during these imports? If my CSV file contains rows with 3 columns (name, email and phone), how I can prevent uploading the data if I already have a lead in the database with that email or phone?
Is this supported by the odoo crm or this functionality needs to be built additionally?