I would be very careful if you plan on using this extensively as it could really skew your reporting and throw a bunch of false positives. According to the docs:
Curious how folks are solving this today without using the CC feature. There are three common scenarios that would result in the same experience you describe:
To get a true CC, you are going to get the experience that the links are tracked for the individual on the To line. There is no technical way around that. However, we do offer tools (like disabling tracking OR just the mkt_tok) from your links. Finally, in some scenarios for using this feature, our customers actually do want to see activity even if it was the CC individual taking action (EA for a CEO). Similarly, if you're CC'ing account owners on many emails going out, they can setup rules in their email client to store these emails in specific folders, as well as understand that the email should not be interacted with unless they are taking action like replying to the thread (which is the primary use case for this feature).
One final piece that may be confusing for people is that this is not a Marketo auditing feature, like our BCC experience. In the future, we may expand our email archival capabilities to offer more functionality. But, this CC feature we launched is intended for customers who do truly want to create threads from the Marketo emails and feel that the benefits are essential to how they do business. For some of our customers in Financial Services industry, this is a key way they intend to send important marketing correspondence to smaller, select audiences.