You're making the assumption that email is the right medium for this kind of information. But people are busy, their in-boxes are already too full, and they have too much important email to read without being interrupted by unimportant stuff.
As one of those busy people (I'm a senior developer), I would not want to receive those kinds of emails from a vendor of a product I'm using. Receiving that information as emails means that I have to do the work of saving the emails that I find useful, and also that I get interrupted by the emails that I don't find useful. I'd much prefer for the vendor set up a well-organized web site that has FAQs, tutorials, etc. that I could search or bookmark. Make it easy to find that information from the main "help" page of your product. Also, create a blog on your web site for product news. If it's useful, I'll subscribe to it in my RSS reader and read it when I have some spare time. (Make it a real blog. Don't assume that I want to follow your company on Twitter or Facebook, where there are all kinds of ads and other junk competing for my attention.)
