After checking this matter with fellow MVP's in Exchange Server, this is what was determined.
Exchange Server does not put a delay in place between Out of Office messages. When OOF is enabled on a mailbox, it creates a list stored on the mailbox containing all recipients which have received the OOF message.
Exchange only sends One (1) OOF message to internal and external recipients.
This list maintained on each mailbox is reset when OOF is disabled on the mailbox and re-enabled.
There is no easy way using native tools provided with Exchange to modify this functionality. It would be possible however to clear the OOF lists on mailboxes on a schedule through creating an external script.
Hope this information has been useful.