Maybe in went into their trash folder. Happens to me sometimes when clients email me, the trash can be a annoying esp if your forget to check. You could try emailing from a hotmail or yahoo account as those don't ever go into the trash.
Be interested to find out my self.
anything from 660 - 1500 a day would be expected.
Regards
Josef Horhay
Mixing Engineer
www.acoosticzoo.com