If you still have issues with receiving emails, remove your email account from the Mail app and then add it back. Before you re-add the email account, log in to your email from the website to verify that all of your email is there or check if your email is saved somewhere other than your iOS device.
To remove and add your email:
If you don’t receive the email in the next 2 minutes please check your junk folder, and add [email protected] to your safe sender list.