How to get html elements from a string?

How to get html elements from a string?

I am creating an ASP.NET MVC 4 site and there is a function where I parse
emails via Pop3 protocol. So after I fetch an email, I have the html coded
email in a string. I want to use the html DOM elements like classes and
id-s, to get data from the email. It would be simple if I can use jQuery,
but I do not find any way to use it. Is there any solution to use
something like jQuery from an MVC Controller to select the proper data?