One of our MOSS servers was not sending out any alert notifications anymore. I'm not sure when it stopped working but recently users started complaining about it.
When I subscribe to a new alert I still get the 'New alert' notification, but that's actually a different mechanism than the actual alerts.
I double checked my antivirus settings but no luck.
Then I found some posts regarding the job-immediate-alerts property:
stsadm -o getproperty -propertyname job-immediate-alerts -url http://moss
stsadm -o setproperty -propertyname job-immediate-alerts -url http://moss -propertyvalue "every 5 minu
tes between 0 and 59"
Operation completed successfully.
stsadm -o getproperty -propertyname job-immediate-alerts -url http://moss
If you get that the property doesn't exist you need to set it in order to get immediate alerts working again. There are a lot of these properties that can be configured:
WSS 2.0: http://office.microsoft.com/en-us/winsharepointadmin/HA33.aspx
WSS 3.0: ? (a lot of the WSS 2.0 properties apply)