Is the port open? Firewall permissions in place?
Further make sure you have configured SMTP configuration in Web.Config:
<system.net>
<mailSettings>
<smtp from="abc@somedomain.com">
<network host="somesmtpserver" port="25" userName="name" password="pass" defaultCredentials="true" />
</smtp>
</mailSettings>
</system.net>
If needed, have a look at this Microsoft Video tutorial:
Use ASP.NET to send Email from Website[
^]
If needed, there are lots of article on this very site on how to send emails.