客户端正在使用哪些电子邮件？

This is not "exactly" a programming question, but it's highly related. We are writing an app that sends out email invitations for a client (no, it's not spam). Their designer gave us an HTML and CSS template to use which is fine. The problem is that it looks like crap in Outlook 2007 because Microsoft decided to use Word (of all things!) as the This is not "exactly" a programming question, b