iCloud e-mail on PC - erases text when it saves

When I am writing an email on my work PC, in icloud, it automatically saves as I go along. However, when it saves, it highlights all the text. I type fast. So the minute it highlights the text, my typing erases what I have written and overwrites it. I have tried to "undo", but it's gone. Is there a fix for this? Or a way to get it back?