How to reply outlook email with same HTML format of body content

Please help, How to reply outlook email with same HTML format of body content to same sender.

I can able to reply email in string format of body content but cant in html format

Hi,
Did you check IsBodyHtml option.
isHtml

I used this "IsBodyHtml"option, but its converting into string format which means all formatting are gone

When you reply to the sender by send lookout mail it takes the default formatting of the account holder .
(e.g:font color,font size)

Hi, Please send if you have any sample file for this email reply.