Help - email replies wider than screen

Hi -

I'm hoping somebody can help me with this issue. Very often when I reply to an email on my iPhone the email I am writing is wider than the screen itself. The text does not seem to fit the screen. This means when typing and reviewing an email you can't read the email without scrolling side to side.

This is such a basic feature of any client it frustrates me, especially as I need to use my phone so much for work. I've also had the same problem from time to time on ipad. Can anyone help or offer advice / a work around?

Cheers