Yes, that is infuriating. We just had our house "energy checked" to find out if we qualify for a big government rebate on a new furnace. The idiots had my name spelled wrong on the email and I pointed that out and gave him a new, "easy" alias email to use. I made him cross out the old one and write in the new one on the form.
So a month later, when we still haven't gotten his report, I email him and he emails back that he sent it to [the original, wrong address] and to check the spam folder. Good thing you can't slap people through email.