Sure you can! In fact, we highly recommend it. It's extremely important to make the most of turboSMTP's services and guarantee the highest deliverability.
Plus, it will minimize the references to BDWEBIT in the header of your sent emails. And it's 100% free.
Please configure manually your DKIM and SPF only if you are skilled enough: that is, if you are familiar with these strings and you can edit your domain's DNS settings. If you're not sure how to manage them, ask your hosting company.
If your provider doesn't allow you to modify your DNS records, you can create another domain from which to send emails.
DKIM AND SPF SETUP
Add the following DNS records in the control panel of the domain you are going to use as "sender":
This is a TXT record that should be added to the domain of the envelope address (example.com)
Two records that should be added to the subdomains "bdwebit._domainkey" and "bdwebit._domainkey.email"
They can be added as TXT records.