How do I setup alerts?

I am trying to setup alerts so that I am e-mailed when a node goes down.  No matter what I do on my SMTP server or on the alerts settings, I always get:

Oct-02 14:32:41.07 : 2484 :   Error Sending E-Mail via SMTP Server (xxxxxx).
Oct-02 14:32:41.07 : 2484 :       To: xxxx
Oct-02 14:32:41.07 : 2484 :       CC:
Oct-02 14:32:41.07 : 2484 :       BCC:
Oct-02 14:32:41.07 : 2484 :       Trigger Subject Pre-Parse:Alert: ${NodeName} is ${Status}
Oct-02 14:32:41.07 : 2484 :       Trigger Subject Post-Parse:Alert: xxxxx
Oct-02 14:32:41.07 : 2484 :       Trigger Message Pre-Parse:Alert: ${NodeName} is ${Status}.
Oct-02 14:32:41.07 : 2484 :       Trigger Message Post-Parse:Alert: xxxxxx is Up.
Oct-02 14:32:41.07 : 2484 :       The message could not be sent to the SMTP server. The transport error code was 0x800ccc15. The server response was not available
 Error Number--2147220975
Oct-02 14:32:41.07 : 2484 :       AlertID=1    NetworkObjectID = N:15

Can someone please help.

I bet you are using McAfee.  There is a built-in Access Protection feature included in the newer releases of the software.  If you are not I apologize but if you are I bet that very feature is blocking port 25.  If not, again my apologies but past experience shows port 25 being blocked supplies people with that very error message.  Please let me know what you find.....

Yes we are using McAfee Viruscan Enterprise 8.00.  We are actually planing on getting rid of McAfee here in a couple weeks and going with new virus/spam control.

McAfee was the problem.  After disable the ON-Access demand I was able to smtp e-mails.

 Now the issue is that the testing portion works and I set my alerts to monitor, they aren't working.  I set up alerts so that when a node goes down I am e-mailed.  After setting it up, testing it (and working), I turn off an access point and I don't recieve an up or down e-mail.

How exactly do you have it set up?  Do you have time limits on the link status set before it will generate an email?  I have seen this before but it was not sending the email when the link was broken because it was only down for a minute or so and the alert was configured to send out a notice only if the status was down for 5 minutes or more. 

This seems to be an issue that is more common than I originally thought I got mine to email from a reboot of our server after the updates had been applied. I know that there has to be a better answer to this since the updates did not require a reboot, and a typically windows 2003 production server can not always be rebooted based on other buisness requirements of that server.

Is there another fix for his issue, other than a Reboot (in case rebooting only fixed my situation)?