I'd personally tie a domain to a paid email account hosted by a provider that is in a sound market position (not e.g. Yahoo), doesn't have a reputation for arbi

I'd personally tie a domain to a paid email account hosted by a provider that is in a sound market position (not e.g. Yahoo), doesn't have a reputation for arbitrarily revoking accounts (not Google), and doesn't have overly aggressive spam controls (not Microsoft). That doesn't leave many options.