<p>Optional parameters:
- abbrev: (boolean) Abbreviate long mailbox names by replacing the
middle of the name with '...'?
DEFAULT: Yes
- basename: (boolean) Use raw basename instead of abbreviated label?
DEFAULT: false
- heading: (string) The label for an empty-value option at the top of
the list.
DEFAULT: ''
- inc_notepads: (boolean) Include user's editable notepads in list?
DEFAULT: No
- inc_tasklists: (boolean) Include user's editable tasklists in list?
DEFAULT: No
- inc_vfolder: (boolean) Include user's virtual folders in list?
DEFAULT: No
- iterator: (Iterator) Tree iterator to use.
- new_mbox: (boolean) Display an option to create a new mailbox?
DEFAULT: No
- optgroup: (boolean) Whether to use <optgroup> elements to group
mailbox types.
DEFAULT: false
- selected: (string) The mailbox to have selected by default.
DEFAULT: None</p>