How do i put html codes inside my div?

the html code is coming from .msg file

MailItem item = (MailItem)app.CreateItemFromTemplate(@"C:\Users\elayronj\Desktop\Sample\sample.msg", 
Type.Missing);   

string body = item.HTMLBody;  

my problem is, when i get item.HTMLBody and display on the div/iframe, 
its replacing the above html tags.