The monitor issues feature allows users to subscribe to certain issues and hence get copied on all notification emails that are sent for these issues.Depending on the configuration, sending a reminder to a user about an issue can add this issue to the user's list of monitored bugs.Users who reported the issue or are assigned the issue typically don't need to monitor the issue to get the notifications. This is because by default they get notified on changes related to the issue anyway. However, administrators can change the configuration to disable notifications to reporters or handlers in specific scenarios.