If you've realized that some of the entries to one of your forms hasn't reached you, don't panic. Go ahead and put in a support ticket, because we need to get it fixed so it will reach your email as it's supposed to.
Meanwhile, you can check all past entries by going to your Dashboard. Once there, click on 'Entries' underneath 'Forms' and a list of entries will appear. It shows entries one form at a time, and you can switch between forms by using the dropdown in the upper righthand corner of this screen. This will show you all past entries to your forms, whether they made it to your email or not.
If you need to resend one of these entries for any reason, simply click on 'View', then on the righthand column, under 'Notifications', click 'Admin Notification'. Enter an email address if you need to send the entry to a different email that it was originally set up to send to. Once finished, hit 'Resend Notifications'.