That can't be avoided short of having a mail service with plentiful full aliases on a shared domain. They could just use the heuristic that unless you're at one of the well known email providers like Gmail, your domain name might be personal and therefore count as part of your global identity, without even considering what comes before the @.

So it doesn't really matter much whether I go with [email protected], or [email protected].

To deal with that for good you'd need a pretty large set of domain names to use for this purpose.