If you are using a contact form in Prestashop, to avoid sending spam, for security reasons it is advisable to enable SMTP authentication. You can do this by following the steps below:
1. Log in to your Prestashop Administrator environment.
2. From the vertical left column, select "Advanced Parameters" and "E-mail".
3. In the "EMAIL" category, select "Set my own SMTP parameters (for advanced users only)"
4. State the following :
1. Your domain.
2. localhost
3. Your contact email (the one you will use to send emails) e.g. info@yourdomain.com where yourdomain.com, your domain.
4. Your email password.
5. None
6. 25
And finally save your changes.