HTML or Text e-mails ?

This is a common question, some will say HTML is the only way others will go completely against it.

HTML e-mails can be much more impact-full then boring plain text e-mails, on the other hand plain text e-mails have greater chance to reach the reader as more and more em-mail clients and anti spam software filter out HTML emails and their images. The rule of thumb remains that you need to let your readers decide for themselves, as they opt-in you list give them the choice between text and HTML.