iOS 10 has added filtering to Mail, which is sometimes more efficient than search at finding what you're looking for. To use filters, simply tap the filter button at the bottom left, then tap the current filter in the bottom center. Now you can set your filters - you can filter by To and CC addresses, Unread and Flagged, and you can have it show only mail with attachments or only mail from VIPs. Once you have set your filters tap "Done" in the top right and you will see a filtered list of your emails.
Email and Messaging
In previous versions of iOS if an email had replies to it, you would tap on it and be sent to a page with all the response emails that you could then access. iOS 10 cuts this out with the addition of conversation view. From your inbox you can tap on the double arrow button to the right of an email and it will show you all the response emails right there, rather than taking you to a new page to list them. It simply cuts out a step, making navigation slightly faster. Close it by tapping the double arrow button again.
One of the smaller new features of iOS 10 is the ability to quickly unsubscribe from an email mailing list rather than searching for a tiny unsubscribe link somewhere at the bottom of the message. Emails identified as coming from a mailing list will have a message at the top telling you that it is from a mailing list and giving you the option to unsubscribe. Tap the unsubscribe button and a confirmation pop-up will appear, tap the unsubscribe button to confirm or cancel button if you don't want to unsubscribe.
Upon installing iOS 10 you may notice that new emails within a thread show up at the bottom of the thread by default (the thread is reversed, oldest at top, newest at bottom), whereas they used to show up at the top. If you don't like this, you can switch it back by heading to Settings -> Mail and scrolling down to the "Threading" section where you will see a toggle for "Most Recent Messages on Top." Turn it on and you will be back to normal.
To stop screen effects on your device navigate to Settings -> General -> Accessibility -> Reduce Motion -> ON.