The mailbox properties will only show that the Mailbox size is 4194303 if the mailbox is over 4GB in size.
When choosing to synchronize or perform a Run now operation on Select mailboxes the mailboxes are listed by name. Double-clicking the name of the mailbox will display the properties for that mailbox. If the mailbox is over 4GB the Mailbox size property will show 4194303 and nothing larger.
Note: This should not affect the archiving of the mailbox.
Symantec Corporation has acknowledged that the above-mentioned issue is present in the version(s) of the product(s) referenced in this article.
There are currently no plans to address this issue by way of a cumulative hotfix or service pack in the current or previous versions of the software at the present time. This issue may be resolved in a future major revision of the software at a later time, but is not scheduled for any release. If you feel this issue has a direct business impact for you and your continued use of the product, please contact your Symantec Sales representative or the Symantec Sales group to discuss these concerns. For information on how to contact Symantec Sales, please see http://www.symantec.com.