You have said both "post blogs on websites" and "post blogs to certain newsgroups" and these are very likely two quite different activities. You can use Thunderbird to post to newsgroups, as it can act as a newsgroup client. Some newsgroups also support posting via email, which would also be something Thunderbird could help you with. Personally speaking, Thunderbird wouldn't be my first choice as a newsgroup client. How you post a blog to a website depends on what support they offer. Some have a webpage that you visit to post. Some, like wikipedia, let you do it "in situ", again via the browser. A few will accept submissions made by email, but there is no single "one simple way" to do this. On this particular Mozilla support website, you just click a button and fill in your new post or a reply to an existing post. You need to do some research, or provide some details about where you wish to post for anyone to be able to give you more detailed (and more useful!) guidance.