The "+" symbol is easy to detect. The other benefit for apple is that if a generated email address for Home Depot has non Home Depot content, it's easy to bloc

The "+" symbol is easy to detect. The other benefit for apple is that if a generated email address for Home Depot has non Home Depot content, it's easy to block, since it's clear it got sold to a email marketing company. And then Apple can then threaten the corporations to not sell their mailing lists or risk being cut off from sending to icloud, or worse, having a header in the email from Apple saying that "Home Depot doesn't respect your privacy and sells your email address to 3rd party marketing companies. Here's a telephone number where you can complain."