All tasks have several alert conditions that you can configure.
These task-level alert settings work in concert with the solution-level alert settings. If the solution-level alert settings are left blank, then the task-level settings will not cause any alert e-mails to be sent. (However, the task-level settings will still cause the task's colour in the Monitor tree to change to yellow or red if the warning or error thresholds are crossed.)
The basic set of alert conditions for tasks is shown below. Some tasks define more alert conditions in addition to these.
Note that there are multiple tabs possible here - one named 'Default' for new tasks. Each of these tabs represents a different Alert Profile. Alert Profiles are a simple way to configure alert conditions differently for different e-mail addresses.
Example: You could create one alert profile for support person A that e-mails them when the input queue size reaches 10, and another profile for support person B that e-mails them when the input queue size reaches 100. For both of these alert profiles, you would use the "override solution-level e-mail address lists" option and enter the e-mail address for the support person in question there.
Right-click on the Alert Profile tab to copy or rename that profile.