# File lib/vmail/imap_client.rb, line 140
    def list_mailboxes
      log 'loading mailboxes...'
      @mailboxes ||= (@imap.list("", "*") || []).
        select {|struct| struct.attr.none? {|a| a == :Noselect} }.
        map {|struct| struct.name}.uniq
      @mailboxes.delete("INBOX")
      @mailboxes.unshift("INBOX")
      log "loaded mailboxes: #{@mailboxes.inspect}"
      @mailboxes = @mailboxes.map {|name| mailbox_aliases.invert[name] || name}
      @mailboxes.join("\n")
    end