I think trying to frame "customers mark unwanted email as spam" as a customer problem is just shouting at a river at this point.
How I design my, admittedly not corporate, email delivery system is to require the user explicitly click "Send this to my email" every single time. No email is sent without a user clicking a button painfully explicitly asking for it.
Honestly treating e-mail like sex where it requires enthusiastic continuous consent feels like it should have always been this way. It's really not that hard to have a button and have receipts/tracking to only be on your account page unless they ask for it.
Yeah but like, the guy who mentioned the customers marking emails as spam even though they requested it, did the exact same thing. They consciously solicited a quote and specifically asked for it to be delivered by email, and then for some unknowable reason, marked it as spam despite having completely 100% consented to receiving the email.
> for some unknowable reason, marked it as spam despite having completely 100% consented to receiving the email
Ordinary users aren't very interested in what is and isn't spam (nor are legislators, for that matter). It doesn't help that organisations like DMA lobby to tinker with definations. Unsurprisingly, a large proportion of users think spam is just "email I don't want". So they click on "mark as spam".
How I design my, admittedly not corporate, email delivery system is to require the user explicitly click "Send this to my email" every single time. No email is sent without a user clicking a button painfully explicitly asking for it.
Honestly treating e-mail like sex where it requires enthusiastic continuous consent feels like it should have always been this way. It's really not that hard to have a button and have receipts/tracking to only be on your account page unless they ask for it.