Loss of formatting after emailing html document

[BAREJAA]

Dear Ulrik,

Firstly, thank you very much for making your code available to use. I can view the html output in the desired format on my Mac, but when I email the html file (e.g. one-column.html), download, and then open the file, the output is just plain text (I emailed the file to myself and tried to download and open it on my work PC using Chrome.) I don't know anything about html and css, so apologies for this basic question.

Thanks again!
Akshay