You can insert drawings and handwriting into emails by long pressing on the body of an email until a bar of options pops up. Tap the right arrow until you see "Insert Drawing" and tap on it. Now you have a variety of tools to use for your writing/drawing. When you are finished, hit Done in the top left and it will be inserted into your email.
Email and Messaging
iOS 11 introduces two new screen effects on the iPhone. Echo and Spotlight join Balloons, Confetti and more as a fun way to enhance your text messages. iPhone owners running iOS 11 or later can send the Echo and Spotlight effects to other iPhone owners also running iOS 11 or later. Here's how:
iOS 11 introduces a new screen effect for the Messages app called Echo. This effect sends multiple bubbles of whatever word(s) you have typed. You can send Echo text messages to other iPhone users running iOS 11 or later by following these steps.
iOS 10.2 adds two new screen effects to the Messages app: Celebration and Send with Love. The 10.2 screen effects join the original 5 screen effects introduced in iOS 10. Here's how to send the Send with Love or heart screen effect on your iPhone or iPad: