Author:Jonathan Maltz MVP
MS Article ID : 555030

SUMMARY
After the installation of the SMTP service on Windows Server 2003, the SMTP tree may not appear in the IIS Manager console.

SYMPTOMS
After the installation of the SMTP service on Windows Server 2003, the SMTP tree may not appear in the IIS Manager console.

RESOLUTION
Method 1: Click the "Start" button, then "Run…" and type:
regsvr32 %systemroot%\system32\inetsrv\smtpsnap.dll
Alternatively, %systemroot% can be replaced with the drive Windows Server 2003 is installed on

Method 2: Uninstalling and re-installing IIS including the SMTP service has also proven to fix the problem, it is, however, recommended to try method 1 first.