Yes, you'll have authentication enabled for both incoming and outgoing mails.
DKIM (DomainKeys Identified Mail) is used as a mean to verifying incoming email. It ensures that incoming messages are unmodified and are from the sender from whom they claim to be. This feature works to prevent incoming spam messages.
SPF (Sender Policy Framework) is enabled by default as well. SPF system allows you to specify servers and IP addresses that are authorized to send mail from your domain(s). This feature works to prevent outgoing spam messages.
You can disable these services if you like from cPanel > Authentication. But it's recommended you don't do that.
You can also set up some advanced option from this page. They aren't required to be changed and please approach with caution if you want to change any of those advanced options.