The simple email subscriber plugin allows user to register their email to the wordpress subscription list
The plugin is configured to send email whenever a new post is PUBLISHED, that is if you schedule your post, it will send email only if the post is available to users.
WordPress allows user to do all sort of random setups, which can mess up the url. This plugin uses one of the wordpress standard url getter: home_url() as your website homee link. to set it up, go to settings->general and define "wordpress address" to your blog home page.
Alternatively, if you wants to use the get_site_url() method instead, feel free to go into the plugin code and change all the home_url() to get_site_url() and setup the "site address" to be your home url.