That means creating a steady stream of material, distributed to a discrete list of reading customers, who will tell you whether they want to continue receiving this informative copy or to stop clogging their inbox. That is, it will all come down to the words you choose. Your newsletter content should closely align with the marketing messages that you've worked hard to hone. In the best case,
your newsletters should reflect the design email list and messaging communications you decide to produce on your website. This assumes that your website content is up-to-date, which for most businesses, this is often not the case. Your website can also serve as a source of ideas for newsletter content. For example, if you've focused on your services on the website, and one of those services is improving communication networks, one 500-word newsletter can detail how to differentiate a high-quality network from one that isn't (preferably without mentioning your product in the body of the newsletter).
The goal is to subtly demonstrate your experience and expertise with the subject at hand, not to sound like an infomercial. A boilerplate statement at the end of the newsletter may include the brief fact that your organization installs facility-wide communication networks, but that should not appear to the reader as the main reason for sending it. Is the sales pitch an afterthought?