Press Ctrl+Shift+B to open the address book.
The address book lists everyone you have sent mail to or explicitly added. You can search by name or address, edit contact details, and organize contacts into groups.
Groups let you write to multiple people with a single address. Select a group in the address book and press Enter to expand it and see its members. To compose to a group, type the group name in the To or Cc field and select it from autocomplete.
Open the address book and use the Groups pane to create, rename, and delete groups, and to add or remove members.
Group names must be unique, regardless of letter case (“Team” and “team” count as the same name). If you try to create or rename a group to a name that already exists, QuickMail tells you the name is already in use and leaves your text in place so you can choose a different one. Groups are never merged.