I have created a MP that will check a target server’s SMTP service by using telnet.  The script included in the sample MP will require a command (to run on the target server) and an expected response (usually a string).  The VBscript part of this MP uses the Toolsack Baseline dll (from Toolsack Software) to perform the telnet functions.  When you import this MP, can you find the example rules by changing the scope of the Rules View in the Authoring pane to Management server.  You can implement this MP in a SCE environment as well. 

This is better than a port check, as it allows you to send an SMTP command (like EHLO) and check the string returned to make sure the server is open for business. A readme is included with the MP download.

Note: Which ever server you pick to run the scripts/rules from this MP, it must have the Toolsack baseline package installed.  You can visit the site www.toolsack.com to download the DLL.

You can find the MP in the downloads section called “SMTP Check for Ops Mgr 07″ or you can download it from here.