You can use filters to temporarily show only certain email messages—the ones that meet all the criteria you select in the filter list. For example, if you select Unread and Only Mail with Attachments, you see only unread messages that have attachments.
You can also specify which email accounts are visible in Mail when a particular Focus is on.
Go to the Mail app at the bottom.
Tap “Filtered by,” then select or turn on the criteria for messages you want to view.
Tap . See Set up a Focus on iPadSearch for email in Mail on iPad