Great. The thing I like is that you get maximum flexibility, and good web interface. For example: I run a mail server which handles mail for some subdomains, and the root domain mail I route through them. Every time I give an email out to a company, I name it company-name@one-of-many-short-fastmail-domains.com. I never have to worry about spam from those email address, as I can filter and cycle those at will.