Chances are, you do — if you have reasonably small and nimble fingers that profit from as short a distance as possible between keys; and if you can reflow messages so your eyes can profit from the narrow column to scan faster.
Not all fingers are small and not all messages can be reformatted, though. It also makes sense to use the wider landscape mode for typing and reading (or admiring photos). In iPhone Mail, you can profit from both portrait and landscape's advantages.
Type with a Big Keyboard and Read on a Wide Screen in iPhone Mail
To read messages on a wider screen and use a bigger keyboard to compose mail in iPhone Mail:
- Rotate the iPhone or iPod touch to landscape orientation.