I misphrased my query; I already run my own mail server and am using a unique e-mail address for every service. I'm wondering if there's a provider with a common domain name shared between lots of users that still allows such a large number of aliases. That would let me use a fake name for anything that doesn't need my real identity, and wouldn't reveal my identity in the case of a breach. Has any e-mail provider found a way to implement this while preventing abuse?