You can adjust your preferences for the Mail app notifications, choose the alert style and Lock Screen appearance, and customize notifications by account.
Default Mail App: Choose the email app for new emails you draft outside of a specific app, such as emails you create using Siri.
Message List: Change settings for your message list, such as showing To/Cc labels, choosing the length of email previews, and customizing swipe options.
Messages: Turn on Set email notifications on iPhone