> I have "load remote content" disabled on my e-mail client so that tracking graphics/pixels do not leak such information to the sender.

Often times that's meaningless as email scanner software will load and inspect all links and images regardless of the human's email client preferences. It basically comes down to can Constant Contact, or similar, detect if a link was clicked by security software or an actual human. And security software wants to look like an actual human because if security software looks like security software it's very easy for bad actors to serve safe payloads to security software and malware payloads to human actors.