For example, in Ramos v. Gap (2025) a California court dismissed a specific lawsuit over tracking pixels in marketing emails. That decision concerned one case and does not settle the question for others. If you send tracked emails to people in California, ask a US lawyer about current case law.
What HawkOpen does: every tracked email carries a notice with a link to turn tracking off, and you can exclude addresses, domains or countries from tracking. A notice in the footer does not settle whether you comply with CIPA.
Where rules that require consent apply, tracking may start only after that consent has been obtained. The link in the message lets the recipient withdraw consent later.