How to Geenrate HTML string and render as a multi line

Hello Sir

I have a one string with the HTML content and the HTML content contains the "IF" condition for different email client
When i generate the string and Display the output using "view source" (^u) whole the content is generate as minify ( Single Line)

Can you please advice how can i generate HTML string without minify ( Multi line )

minify structure is creating a problem in "OUTLOOK"

Bhavik Shah