Normally when a member leaves a group it will not be possible for anyone else to tell except through looking at the member index. However, there are two options that can send notifications. In the group go to the Settings section and choose Member workflow. There you will find two settings:
- Notify group administrators on leaving. With this option an email will be sent to the administrators of a group whenever a member leaves.
- Notify system administrators on leaving. With this option an email will be sent to the system administrators whenever a member leaves. Note that only system administrators have the option to change this setting.
If necessary you can also stop members leaving.