# File lib/vmail/contacts_extractor.rb, line 47
  def set_mailbox_prefix
    mailboxes = ((@imap.list("[#@prefix]/", "%") || []) + (@imap.list("", "*")) || []).map {|struct| struct.name}
    @prefix = mailboxes.detect {|m| m =~ /^\[Google Mail\]/}  ?  "Google Mail" : "Gmail" 
  end