how can i set lines gap between each lines

i like to give two lines space between the each lines in new mail ? how i can set?

make sure microsoft word is your text editor
(tools/options/mail format tab
under message format
make sure it says rich text
and word is selected as editor)
open new mail
click in body of mail
then format/paragraph
indents and spacing tab
in line spacing select multiple and change to value you want