Not being able to access your emails can be conflicting! Please ensure of these steps to make sure you receive emails. To access most of these steps please visit your settings, play store or passwords/accounts.
Ensure automatic email sync is enabled
Clean your devices storage
Ensure you have the correct password for the email account
Clear cache and data from your email app
Make sure you mailing app is up to date
Try removing and re-adding the mailing account to your email.
Ensure email notifications are toggled on