Frequently, the person charged with looking after an instrument will need to contact all users (e.g. maintenance schedules, malfunctions, missing accessories). Bumblebee has two email lists for each instrument to which users can be subscribed.
You can choose which of these lists you want returned and for which instruments you require the list of email addresses. Bumblebee will only list an email address once even if it is on multiple lists.
Note that Bumblebee doesn't actually send emails to these lists; rather, it returns the list of email addresses in such a way that you can copy them into your own email client.
A user's subscription options are managed through the Edit Users form.