I am trying to get a hosted Avenir LT W01_55 Roman webfont to display in an HTML email for iOS devices.

The font is hosted here 'http://fast.fonts.net/cssapi/af395689-2c2c-43f9-9e8f-68fdef40ecac.css'

I am using the @import method like this in the head tags

<style type="text/css">
     @import url('http://fast.fonts.net/cssapi/af395689-2c2c-43f9-9e8f-68fdef40ecac.css');

     td {
     font-family: 'Avenir LT W01_55 Roman', Arial, Helvetica, sans-serif;}
     .bold {
     font-family: 'Avenir LT W01_55 Roman', Arial, Helvetica, sans-serif;}

And reference it in the HTML content like this.

<td style="border-collapse: collapse; font-family:'Avenir LT W01_55 Roman', Arial, Helvetica, sans-serif; font-size:25px; line-height:34px; color:#1d1d1d;  margin:0;font-weight:bold;">

It works on the web version but not after sending the test emails. Am I coding it incorrectly?