The customer support is non-existent, but the service itself does what it's supposed to and has vastly cut down on my trash emails for me.
I personally add a + symbol followed by anything with your email address, if that is not good enough for you, you might want to look at Throttle.
Throttle lays a handful of handy features on top, besides making the whole system easier to use.
I always had a passion to work with emails. SMTP, POP, and IMAP are filling my stomach with butterflies (something must be off in my brain) and after having sold VoilaNorbert, I was still eager to build Python code that connects to SMTP servers through sockets...