This website and its sample code creates a template of sorts, absent of design or layout, that will help you avoid some of the major rendering problems with the most common email clients out there β Gmail, Outlook, Yahoo Mail, etc. While not plug and play (you know, you'll have to do some work ;-), it will provide some helpful examples and snippets that will keep your email design rendering as true-to-form as possible.
The email newsletter is a powerful marketing and communication tool that has various useful functions. It reminds your users about you; it informs users about your products; it tells them what you have been up to; and it helps you build a unique relationship with them. Users like email newsletters if the newsletters bring them value.