Enterprise Vault Exchange mailbox archiving based on quota keeps a percentage of each user's Exchange mailbox storage limit free. When you use archiving based on quota, Enterprise Vault estimates how much mailbox space will be saved by archiving items. This estimate enables Enterprise Vault to archive the correct number of items to achieve the quota-based archiving target.

This document describes the calculations that Enterprise Vault performs when it makes this estimate.

The information in this document applies to both of the following Exchange mailbox archiving strategies:

• Archiving based on quota only
• Archiving based on the age of items and on quota