This is a weird issue. I think it has to do with user experience, but let me know if I should post it on another SE site.
One one hand, we have many customers who tell us they didn't receive their order confirmation e-mail. We ask them to check the Spam folder, and most of the time it's there, of course.
On the other hand, we have customers who specifically complain about our order confirmation emails. I know it because we use Amazon SES which always sends us a copy of complaints it receives.
Here's what the order confirmation looks like:
Of course the information has been edited out, but otherwise this is exactly what they receive: light text, to the point, no upsell, no marketing. It even has an unsubscribe link, although the email is transactional and therefore exempt.
I can't find anyone talking about an issue like this. But still, enough people complain about our emails for our sender reputation to be affected, and for me to be concerned about this
From the user experience standpoint, do you think making the order confirmation emails opt-in is a good idea? This way they will get an e-mail only if they specifically request it on the payment success page.
It sounds like it could work, but I have never heard or seen of anyone do this.