Yes, users are free to still continue whatever means they have used in the past to opt-out, including at the client level. We don't (and can't) prevent any of that.
Of course you can't prevent it, however one of your application's goals is to work around email client filters that would block traditional tracking methods. Just to be clear, I have no problem with what you are doing.
I would like to know if blocking images is enough to not be tracked. Do email clients have sufficient image blocking or do they let through images specified in CSS (or similar) through?
I would like to know if blocking images is enough to not be tracked. Do email clients have sufficient image blocking or do they let through images specified in CSS (or similar) through?