This. I use my own domain for all of my email, and don't like to give out my gmail email address. This is a really bad idea, and should be one of your top priorities to be changed. Getting "bad" emails is part of the cost of doing business, so stop hiding behind the "it costs us money to send emails" line. So what?! You are eliminating users by doing this, which in the long run costs you WAY more than sending to some non-existent emails. Just validate the email addresses so you know they exist, and maybe re-check in 30 days - that would probably eliminate most of the "testing" emails from your system.
yes. we realize that we might loose some users just for the sake of not having an email acc wit a popular provider. for some reason we assumed that users would have an acc with one of them and use it or try without signup..we dint think of the users who would want to signup but with an alternate email of theirs. back to drawing rooms on this! :)