Typically, your iPhone would have you shake the device to undo moving an email or typing. It’s a pretty neat feature that, many of us would agree, is a pain to do. However, if you want to undo a typing mistake, you don’t have to throttle your phone.
Instead, swipe left with three fingers. This sequence will trigger the undo action. Additionally, if you erased text by mistake, you can redo it by swiping three fingers to the right. The only Shake to Undo mechanism still exists in newer iPhones, but you’ll want to remove it from your muscle memory to make room for this faster trick.