Email Application (iOS)

I'm trying to make an email app like Gmail. As gmail app, I got showed up emails in listing. But in detail view page there is some issue with response. In response i got mix type mail response like with attachments, plain text, html. So when response is in html and I load it in UIWebView, then sentence comes in single long line. I want to wrap the long text according to page scale size and as well as for html content, I want show in webview exactly like Gmail. But also when i load html content in Webview, I get extra white space as padding that also I want to remove. There is API with response. Make it as like as gmail app showing mail detail with minimum zoom level and aspect fill without gape. Also want zoom in and zoom out functionality. (Swift only) Regarding API is [login to view URL] (Append with mail ids 261,260,258,231,227 )