What is Monitoring?
SourceForge.net's Monitoring features give registered users the ability to receive mail when changes occur to Tracker tickets, or new posts made in a Forum. Each of these tools (Tracker, Downloads) provide a "Monitor" link or icon which enable the monitoring. Whole projects may also be monitored using the Monitor link on the Develop page.
A list of the things monitored by your account can be seen on your SF.net Monitoring page.
To stop monitoring, you may use the "Stop monitoring" link in the same place you found the original Monitoring link, or remove the monitor on your SF.net Monitoring page.