Automatically create records
With Record Creation and Update rules it is possible to automatically create records in CRM. This is often used to create cases for emails sent to a support queue.
The option Create records for email from unknown senders needs some explanation. If this option is selected then if the sender of an email does not match a record in CRM then the rule will apply and the record (as per the rule creation details) will be created as well as a contact record where the last name is set to the email address of the unknown sender.
If the option is not selected, then the incoming email (or other activity) remains in the queue and a record is not automatically created.
It is not possible to have CRM create the record as per the rule creation details but not create a contact. And I don't believe that the record creation setting in personal options of the owner of the record creation rule are relevant.
Email's cc'd to Queue
If an email arrives in the mailbox for a queue via a cc recipient instead of a to recipient, then the email is still processed by a Record Creation and Update Rule. If you don't want this to happen then add a rule item that tests for the email address in the To Recipients field. I have noticed that there is a semi-colon after the email address in the email so make sure you take that into account in the test. I suggest a test like this:
Emails from CRM Users
When the sender's email address matches a CRM user record, the automatic record creation rule does not resolve the sender to a user record. Only contact and account records are considered. However, this https://support.microsoft.com/en-us/help/3094208/automatic-record-creation-rules-fail-when-the-sender-of-the-email-is-a-contact-and-a-user-in-crm-you-should-specify-a-parent-contact-or-account. suggests that a fix in 2015 will match user records. The article describes actions to be taken in the rule.