In SBS 2008, Forefront Security for Exchange is offered as a 120 day trial during the installation of SBS. If you choose to install this component it is a good idea to regularly review email messages and attachments that may have been quarantined by forefront. This is good for 2 reasons, identifying false positives so you can forward the email to the user as it is a legitimate email with a safe attachment, and also to get an idea of what type of unsafe emails and attachments are being sent to your users which will give you an understanding of what Forefront is blocking. Additionally, when performing a migration from exchange 2003 when you run the move mailbox wizard, Forefront Security for Exchange real time scanner will scan all email in your users’ mailboxes as they are being moved and possibly quarantine previous emails.
To access the quarantine report open Forefront Server Security Administration under All Programs > Microsoft Forefront Server Security > Exchange Server, click continue on UAC prompt, select your server and click ok. Once Forefront Server Security Administration is loaded, expand the report section and select Quarantine.