Change the default setting for the Send Notification Email checkbox for Tasks
|Knowledge Article Number||000003633|
This article applies to organizations that do not have the "Enable user control over task assignment notifications" setting enabled via Setup, click Customize | Activities | Activity Settings. If your organization does have the "Enable user control over task assignment notifications" feature enabled see the Considerations for Email Notification of Task Assignments documentation for more details on how users can set reminder preferences individually in their personal settings.
1. Go to the Home Tab (If you already have an existing Task open click the Edit button, skip step 2, and go to step 3).
Note: This default setting will apply to all Task creation/edit pages under all objects and related lists throughout the application, and can be changed back the next time a non-default value is selected.