Question : Easy SMTP question on Windows 2008 Server

I need to be able to have an ASP.NET application running on IIS7 on Windows Server 2008 send email.   I'm sure there's more than one way but I'm looking for the easiest way that makes the most sense for low volume email sending.

I'm assuming that I can set the SMTP using IIS7 Manager
Start > IIS Manager > {Server} > Features View > SMTP E-mail > Deliver Email to "smtpauth.mycompany.com" or "local.host"

If I choose "smtpauth.mycompany.com" this would be a 3rd party email service that we already use for our company email (smtpauth.mycompany.com) that is hosted outside, right.
Or if I use "local.host"  do I need to set something up in the SMTP Service through the IIS6 Manager?

I'm a little confused.  If I use  smtpauth.mycompany.com then I don't need to have the SMTP Service running at all on the server, right? I only need the SMTP service running on the server if I use "localhost" in IIS7, right?  And I'd only need to run SMTP service on this server if I didn't have an "smtpauth.mycompany.com" running elsewhere, right?

Is my thinking correct?  And if so which is easier and what are the advantages/disadvantages that I have't thought of?    

Answer : Easy SMTP question on Windows 2008 Server

Guide for configuring the SMTP service in 2008: http://www.itsolutionskb.com/2008/11/installing-and-configuring-windows-server-2008-smtp-server/