Disable PopUp via redirect vs via referral URL

Here's what I'm trying to do:

If someone clicks a link in an email I sent them, then I don't want them to see the popup asking them to join the newsletter.

They are obviously on the newsletter, they've just clicked from the email newsletter to my site. Very annoying to then get the popup asking them to join the newsletter again.

Of course they can mute it - but that's cookie based, so doesn't work across devices, browsers, work vs home computer etc.

So here is how I went to try and solve the problem.

When someone clicks a link in an email via Infusionsoft, Mailchimp etc - the click always goes first to the email service's domain, then redirects back to my site.

So I tried to use the "not from specific referrer" setting, but it doesn't work in this case, because I think a 301 redirect is happening -- google analytics also doesn't pick up the email service's link as the referring URL either, it shows up as a direct visit.

If that's still not clear what I'm trying to do - here is more detail:

If I send an email out via Infusionsoft, MailChimp etc - when someone clicks a link in that email, the click first goes to http://app.infusionsoft.com/etc-etc-etc -- which then redirects to the intended page of my site.

I want to know if you can give me advice on how to either force those redirects to show up as referral URL's so that the "not from specific referral" setting works for this use case.

Another solution could be a URL parameter, but this defeats something else I'm trying to do which is - I want to use the PopUp to protect a download - meaning you must join my list to get the download.

I used CSS to hide the close button on the modal, so someone tries to get the content - they can't because the modal is showing over the top of the content.

The user then puts their email into the form, gets the email, clicks the link - the "not from specific redirect url" rule would work - and now the modal does not show, and the user gets the content.

The user now copies that URL and shares it on social media.

Everyone who now follows the shared URL would still see the modal.

The problem with a URL parameter, is that anyone who copied the link, would end up copying the URL parameter as well and so the popup would be defeated.

So I really need a way to make a redirect show up as a referral URL.

Any thoughts / ideas?