i assume that u have any application server , like Tomcat Or Jboss .
in either of them u can define your servlet  inside web.xml file as below :

    <servlet>
        <servlet-name>SchadulerServlet</servlet-name>
        <servlet-class>schaduler.SchadulerServlet</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>SchadulerServlet</servlet-name>
        <url-pattern>/US</url-pattern>
    </servlet-mapping>

this part of above code <load-on-startup>1</load-on-startup> will be cause the servlet class i.e SchadulerServlet starts whenever the app  server get started.

inside the class you can define the Schaduler like Quartz that pass the mails addresses to the mail server in periodic format.
u can user  the mail server like JAMES , this is an Apache product , you can download it from Apache site.it works on port no 25 .
any more question u can ask me .