Manage Outage Notifications?

[Shawn L]

What are people using to manage / send their outage notifications?  We're 
currently using a mostly manual process to identify customers that need to be 
aware of an outage and send out e-mail at $dayjob.  Looking for a way to 
automate it more.  I'd prefer something open source, but that's not a 
requirement.
 
Thanks