The only way to receive an email of your online ADR's is if you entered your email address on the page showing your ADR info. If you didn't enter your email address, you will not receive an email (even if your log-in info with My Disney Vacation includes an email address). When I did our online ADR's I sent them to my email address as well as my husbands and mother-in-law's (that way we all had copies).
If you call and Disney Dining can give you your confirmation numbers, you can go back online, log in, and go to the "My Disney Vacation" link in the upper right hand corner of the screen. A list will drop down with "Dining Reservations" at the bottom. Click on that and you will be able to enter the confirmation numbers along with the phone number associated with the reservations. Click the "Retrieve Multiple Reservations" button if you want to look up more that one reservation at a time. After you have pulled up all your ADR's you can enter your email address (I believe at the top of the page) and it will email you all your info.
Hope this helps. Good Luck!