Preventing unsubscribes in forwarded emails

Question

I am sending bulk html emails, and have the proper "unsubscribe" option at the bottom. If someone forwards such an email, I would like to omit that unsubscribe notice. This is acceptable for two reasons: (1) the forwarded email is no longer a bulk email but rather an email from one person to another; (2) it makes no sense for the second recipient to try to unsubscribe, because they are not subscribed.

There is article describing the situation at https://litmus.com/blog/preventing-unsubscribes-in-forwarded-emails, which also gives a brilliant solution. While that solution may have worked back in 2013 when proposed, it no longer works.

The solution was to take advantage of the CSS cascade and the fact that forwarded html emails often get a <blockquote> tag right after the body. Thus you could set up selectors such as the following:

blockquote .original-only {display: none !important}

The problem is that forwarded emails have both external and internal stylesheets stripped out. And inline styles cannot take advantage of the cascade.

Is there a modern, workable solution?

Answer 1

I'm not sure if there's a reliable way to remove / hide the unsubscribe info from e-mails but, in case it's an option for you (or others), I'll take a different approach.

A good place to handle this problem may be, not on the e-mail page, but on the unsubscribe page.

Once a user, any user, clicks on "unsubscribe", they are re-directed to a confirmation page.

On that page you can:

1. Display the e-mail of the original recipient and a note saying something to the effect of:

   "If this is not your e-mail address, the message was forwarded to you. You are not on our mailing list. There is no need to unsubscribe."

   That method is user-friendly, but not really secure, since the forwardees can still unsubscribe the original recipient for whatever reason.

   You could minimize that problem by having an automated e-mail sent to the original recipient confirming their unsubscribe. Provide a link to re-subscribe.

2. Display an empty input box. Ask the user to enter the e-mail address they wish to unsubscribe.

   This method is less user-friendly (the user is being asked to work), but it's much more secure. Only the e-mail address entered will be unsubscribed. If it's not on the list, nothing happens.