[JoshTriplett]

There's an alternative approach that I think would feel more valuable and worth paying for.

Think about how Apple Pay solves this problem: they give a unique email address to every site. People who have their own domains, or who trust the base+suffix@domain approach and don't think sites will strip off the +suffix, do something similar manually.

You could provide a similar service for sites that don't accept Apple Pay.

Provide an automatic email address (no per-site setup required) for people who expect a few transactional mails ("here's your shipment tracking number"), track (across customers) whether those email addresses get sold to spam lists, flag companies that get caught selling email addresses.

If you're providing the insulating layer on email, you're providing more obvious value to your customers.

[knes]

I actually use the service you described. It is called http://anonaddy.com .

I'm not affiliated to them (discovered them on Producthunt I think) but I use it all of the time for one-off eCommerce websites, newsletters, etc. you can have your own custom domain and anything before the @ is a wildcard and gets automatically created.

It is super easy to "delete" or stop the forwarding of email to these addresses