There have been cases where a lead has 2 emails in the system and is unsubscribing from one, but doesn't realize the other email is still opted in. Normally, they would see it's sent to a different domain and unsubscribe from both, however, they must have rule set up to automatically forward the email to the unsubscribed domain. So to the person, it appears our unsubscribe is broke, when in fact they just don't realize they have a forwarding rule in place.
When I look at the activity log, Marketo sees the email as delivering to the opted-in email address, but when the person replies to the email to angrily say they've unsubscribed 10 times, it's always from the email address they have actually unsubscribed from (hence why I assume they have an inbox forwarding rule in place). Any suggestions? I would think this would be extremely rare, but it seems to actually be happening to us quite often.
We are working on doing some lead merging which might help, but these are different email addresses so it makes it tough to recognize it until the lead complains and I search to find their second email address in our database.