The Notify extension version 2.1 from Novell causes severe performance degradation on Macintosh systems running System 7.x. These performance problems extend beyond network performance slowdowns and include actions as simple as opening your hard drive. You should use the latest release of the Notify INIT which is version 3.0.
Below is an excerpt from the Read Me regarding the release:
NOTIFY v 3.0
This version of the Notify INIT addresses several issues. It includes the fix for a problem with Notify loading on a System 6.x Macintosh with over 8 MB of RAM. It resolves several performance issues when running System 7. And the frequency at which it polls the Netware server for messages has been decreased, which resolves some performance problems on large networks.