this.mails.putAll(mails);
// ����mail id��mail service
for (Map.Entry<String, MailBuilder> entry : mails.entrySet()) {
String mailId = assertNotNull(trimToNull(entry.getKey()), "mail id");
MailBuilder builder = assertNotNull(entry.getValue(), "mail builder");
builder.setId(mailId);
builder.setMailService(this);
}
}
}