If you want  to change the EditForm, NewForm and DispForm Urls of a content type, you could do it as follows:

<?xml version="1.0" encoding="utf-8"?>
<Elements xmlns="http://schemas.microsoft.com/sharepoint/">
  <!--Some defined fields-->
  <!-- Example: Parent ContentType: Item (0x01) -->
  <ContentType ID="0x0100..."  Name="ProductContentType" Group="Custom Content Types"  Description="My Content Type" Inherits="false" Version="0">
    <FieldRefs>
      <!--Some references to the fields used in your content type-->
    </FieldRefs>
    <XmlDocuments>
      <XmlDocument NamespaceURI="http://schemas.microsoft.com/sharepoint/v3/contenttype/forms/url">
        <FormUrls xmlns="http://schemas.microsoft.com/sharepoint/v3/contenttype/forms/url">
          <Display>_layouts/MyProjectName/Product.aspx?mode=display</Display>
          <Edit>_layouts/MyProjectName/Product.aspx?mode=edit</Edit>
          <New>_layouts/MyProjectName/Product.aspx?mode=new</New>
        </FormUrls>
      </XmlDocument>
    </XmlDocuments>
  </ContentType>
</Elements>

However after reading the JOPX Blog post about this, it is better to do this in code and to make an extra feature for this. If you want to clean up (reset) your Custom Urls to the default ones used by SharePoint when de-activating that feature, also that code is included:

private void changeFormUrls(SPSite currentSite, string offerteContentTypeName, bool reset)
{
  foreach (SPWeb currentWeb in currentSite.AllWebs)
  {
    foreach (SPList currentList in currentWeb.Lists)
    {
      foreach (SPContentType currentCT in currentList.ContentTypes)
      {
        if (currentCT.Name.Equals(offerteContentTypeName, StringComparison.CurrentCultureIgnoreCase))
        {
          try
          {
            currentWeb.AllowUnsafeUpdates = true;
            //Change the Form Urls
            if (reset)
            {
              currentCT.NewFormUrl = "NewForm.aspx";
              currentCT.EditFormUrl = "EditForm.aspx";
              currentCT.DisplayFormUrl = "DispForm.aspx";
            }
            else
            {
              currentCT.NewFormUrl = @"_layouts/MyProjectName/Product.aspx?mode=new";
              currentCT.EditFormUrl = @"_layouts/MyProjectName/Product.aspx?mode=edit";
              currentCT.DisplayFormUrl = @"_layouts/MyProjectName/Product.aspx?mode=display";
            }
            currentCT.Update();
            currentList.Update();
          }
          catch (Exception ex)
          {
            //ToDo: Add some logging...
          }
          finally
          {
            currentWeb.AllowUnsafeUpdates = false;
          }
        }
      }
    }
  }
}

Off course you’ll have to pass the name of the content type to this function.

Happy coding

• Operating system VPC: Microsoft Windows Server 2008 Enterprise (32-bit)
• SmarterMail version 7.2.3925 : latest version can be downloaded here.
• MOSS 2007 (but can be used for SPS 2010 also)

Installation

Step 1/8: Installation of SmarterMail
1) Launch the Setup file after downloading the latest version of SmarterMail (free edition).

2) Perform a default installation, don’t fill in a licence key. When you get the screen asking for the system information. Fill in the right information:

In the next screen, leave the DNS details blank, finish the wizard by not activating SPAM checking functionality. Automatically you will receive the configuration screen of SmarterMail.

Step 2/8: Configuration of SmarterMail
1) Skip Activation of SmarterMail. This is not necessary.
2) Add a domain. With the free version of SmarterMail, you can only add one domain. I choose to use [.com] as a domain name. I add “.com” intentionally, because MS Outlook will only allow to send emails which are normally formatted (name@domain.extension)…
So add a domain by clicking the Manage icon, in the navigation pane, click New > New Domain:

Fill in the necessary details. Make sure you select 127.0.0.1 as ip-address for the domain:

3) Adding necessary POP3 users: Select the domain you have just created, and click on “manage”. A new screen will open. In the left navigation of this popup, browse to “Users”. Add a user:

Repeat adding users for all POP3 accounts you want to create.

Step 3/7: Creating Domain in Hosts file
As explained in step 2, I have created a domain with name .com. Now we will have to perform a small changes in the VPC Host file so that this domain can be found.
On the VPC, navigate (Start > Run) to the %systemroot%/system32/drivers/etc/ directory. Open the hosts file with notepad and add the entry of .com. It will point to 127.0.0.1, which is the localhost.

Save the file and exit Notepad.

Step 4/7: Configuring MS Outlook
With these steps performed, it should be able now to test our configuration in MS Outlook (if installed on the VPC off course).
Add the necessary POP3 account, for example:

Test the account by pressing “Test Account Settings …”, you should have green “ok” marks

Step 5/7: Configuring IIS
1) Make sure the SMTP service is installed on your VPC Server. If not, you can add it as a feature. (Start > Settings > Control Panel > Programs and Features > Turn Windows Features On / off > Features > Add Features):

2) Configure the relay correctly: Open the IIS 6.0 Manager (Start > Settings > Control Panel > Administrative Tools > Internet Information Services (IIS) 6.0 Manager). Right-click the SMTP Virtual Server in the left navigation (start it if necessary) and select “Properties”.
Navigate to the “Access” tab and click on the Relay button. Make sure the settings are set correctly:

Step 6/7: Configuring SharePoint
In SharePoint Central Administration, navigate to the “Operations” Tab, and click on “Outgoing e-mail settings”. Fill in the correct details, for example:

Step 7/7: Testing!
You now should be up & running.
Note: make sure your SharePoint profiles contain the correct e-mail addresses. (You can set this manually also by navigating to the SharePoint Central Administration Shared Service provider > User profiles and properties)
For testing, you can also download the Test Sharepoint Send e-mail configuration from Rodney Viana. More information can be found here.

Good Luck!!!

After searching some time, I discovered the MS UrlScan Security Tool had been installed which blocked all calls to the webservice and simply returned a 404 because the url contained a “.” character in the path to the webservice asmx.

You’ll find numerous posts online about difficulties with UrlScan and SharePoint installed together, just don’t mix them

The error I received was:
“There has been an error while loading the form. A required resource could not be downloaded. To try to resume the download, refresh the page.”

These issues should be fixed in the newest (V2) release of PointFire, but yet …

… a good lesson to keep in mind: When developing in SharePoint, try to switch off Pointfire once in a while. (And try to avoid InfoPath as much as possible in your solutions).