Outlook 2007 has a new feature which is provided to it by default only by Exchange 2007.
I recently thought of giving Outlook a try instead of Windows Live Mail. Of course, the geek in me wanted my Outlook 2007 first run experience to be awesome. I wanted autodiscover to work for me.
It turns out if you read a KB article and a technet article you can figure out that for 99% of POP/IMAP/SMTP installations, placing an autodiscover.xml file at a url of http://myemail.com/autodiscover/autodiscover.xml or at http://autodiscover.myemail.com/autodiscover/autodiscover.xml is all that is needed. The format of the xml is very simple.
<?xml version="1.0" encoding="utf-8"?>   
<Autodiscover xmlns="http://schemas.microsoft.com/exchange/autodiscover/responseschema/2006">    
  <Response xmlns="http://schemas.microsoft.com/exchange/autodiscover/outlook/responseschema/2006a">    
    <Account>    
      <AccountType>email</AccountType>    
      <Action>settings</Action>    
      <Protocol>    
        <Type>IMAP</Type>    
        <Server>mail.xmtp.net</Server>    
        <Port>993</Port>    
        <DomainRequired>off</DomainRequired>    
        <SPA>off</SPA>    
        <SSL>on</SSL>    
        <AuthRequired>on</AuthRequired>    
      </Protocol>    
      <Protocol>    
        <Type>SMTP</Type>    
        <Server>mail.xmtp.net</Server>    
        <Port>25</Port>    
        <DomainRequired>off</DomainRequired>    
        <SPA>off</SPA>    
        <SSL>on</SSL>    
        <AuthRequired>on</AuthRequired>    
        <UsePOPAuth>on</UsePOPAuth>    
        <SMTPLast>on</SMTPLast>    
      </Protocol>    
      <Protocol>    
        <Type>POP3</Type>    
        <Server>mail.xmtp.net</Server>    
        <Port>995</Port>    
        <DomainRequired>off</DomainRequired>    
        <SPA>off</SPA>    
        <SSL>on</SSL>    
        <AuthRequired>on</AuthRequired>    
      </Protocol>    
    </Account>    
  </Response>    
</Autodiscover>
Do that, and the next time an Outlook2007 client tries to configure itself, it will.