The start of the retention period is one of the following:

• Modified date. For mail messages, this is the time since the message was received. For files and documents, it is the time since the document was last modified.

• Archived date. This is the date that the item was archived. This setting is useful if you import old items from other mail systems and want to prevent the items from being expired according to their original received date.

You need to decide the following:

• Whether to make Enterprise Vault delete items automatically.

• Whether to use modified date or archived date as the basis for calculating the start of the retention period.