HTML e-mail advertisment

What I am looking for is to create advertising content that can be e-mailed with our product information and turn up in the our list of customers e-mails and not their junk box. I would like a template that I can aletr as we have frequent changes. I can e-mail an excel file showing apprx what we need. I believe it is an HTMP page I am looking for. I am looking for a person I can have a long term relationship with on numerous topics of similar nature over a long period.