Just sending potential or current customers general information about your business is not good content. You need to have good reasons to send out your emails: a sale, advice on a type of product or service, a monthly newsletter type, an announcement or latest news in your field.
For instance, if you sell a clothing line, you do not want to send an email about real estate or politics.
Your emails need to be short, have clickable links either to your site or another where they can read more info and contain an unsubscribe link. (All third-party email services have the unsubscribe link in their templates.)
Bullets are better to use than full paragraphs but short sentences in place are fine. Example:
We build you the best widgets you can get in California and use the finest metal parts that are from the USA.
Our widgets are A-Rated from the American Widget Association (AWA)
Located in California
Best grade metal parts and finishes
Manufactured in the USA
Photos or graphics are good to use but not too many. Having a graphic banner which matches or contains the same branding (your logo, tagline, imagery) to use consistently is advised.