Add a dynamic group to Message Delivery Restrictions

Hello,

We can add a dynamic distribution group to "Message Delivery Restrictions" in Exchange 2010 but what i worry about that is performance. Is that cause a problem in a big organization (more than 1 million daily mail traffic)?

It's a good solution for a group to restrict receiving mails from everywhere. but it may cause performance problem if we generalize for more mail groups or mailboxes. Because when i add a dynamic group, mails delay more than normally.

Thanks in advance.