The Clockk browser extension offers Gmail auto-BCC support.

Open the Clockk browser extension by clicking on the Clockk icon in your browser. Click on the “Email” tab, and then turn on “Enable Gmail Auto BCC”.

Gmail auto BCC

You‘re all done! Send an email from the Gmail web interface, and you’ll see a line appear in Clockk’s Activity view a few seconds later.

Remember: Clockk only tracks the email from, to, cc, subject, and date. Everything else from the email is discarded.