It sounds to me like you are asking if you can distribute an email newsletter by emailing your material to a particular email address and then have it distributed to a mailing list. If you set up "post by email" on your site, your posts will be distributed to your readers depending on how they have chosen to receive your new posts (email, Reader, RSS, etc.) http://en.support.wordpress.com/post-by-email/
Before you set up Post by Email, just make sure that you have a secure email client with a strong password which you are not using anywhere else on the web. Post by Email seems to be vulnerable when people are ignorant about password security.