When you configure a journaling mailbox to accept journal reports, you have to determine the maximum size of the journaling mailbox. As with any other mailbox, the maximum size depends on the data to be stored in the mailbox, the hardware resources that are available to you, and the disaster recovery capabilities for the server that contains the journaling mailbox. In addition to these considerations, you must also consider what will occur if a journaling mailbox exceeds the configured mailbox quota.

When you configure the Prohibit send and receive at (KB) storage quota on a journaling mailbox, the journaling mailbox accepts journal reports until the journaling mailbox reaches the configured storage quota. When the prohibit send and receive storage quota is exceeded, the journaling mailbox stops accepting journaling reports.

Microsoft Exchange doesn't return journaling reports to the original sender as it does with regular messages. Instead, Microsoft Exchange holds the undelivered journal reports in a mail queue and tries to redeliver the journal report until delivery is successful. Although this enables Microsoft Exchange to eventually deliver all the journal reports that are generated, it can be problematic in organizations that generate many journal reports because the mail queues on the affected servers can grow quickly.

To reduce the possibility that your journaling mailbox will reject journal reports because it has reached the configured storage quota, we recommend that you configure your journaling mailbox prohibit send and receive storage quota to the maximum size that your hardware resources and disaster recovery capabilities allow for.

Important:
If you remove storage quotas from journaling mailboxes, configure sufficient monitoring to make sure that you do not exceed your available hardware resources or disaster recovery capabilities.

If you must configure a prohibit send and receive storage quota on a journaling mailbox and expect that the configured storage quota might be exceeded, you can configure an alternate journaling mailbox. For more information about alternate journaling mailboxes, see the "Alternate Journaling Mailbox" section later in this topic. Also, when a journal report is rejected by a journaling mailbox, Event ID 8010 is logged in the Application event log. By monitoring the Application event log for this event, you can be alerted to a potential problem with the journaling mailbox and resolve the situation quickly.

For information about how to configure storage quotas on a journal mailbox, see How to Configure Storage Quotas for a Mailbox.

You might not want to allow rejected journal reports to collect in an e-mail queue when the journal mailbox is unavailable. Instead, you can configure an alternate journaling mailbox to collect those journal reports. The alternate journaling mailbox receives the non-delivery reports (NDRs) that are generated when the journaling mailbox or the server that contains the journaling mailbox refuses delivery of the journal report. When the journaling mailbox becomes available again, you can use the Send Again feature of Microsoft Office Outlook to re-submit the journal reports for delivery to the journaling mailbox.

When you configure an alternate journaling mailbox, this mailbox is used to collect all the journal reports that are rejected across your whole Exchange 2007 organization. If any journaling mailbox rejects journal reports, those journal reports are sent to the single alternate journaling mailbox. Therefore, it's important to make sure that the alternate journaling mailbox and the mailbox server where it's located can support many journal reports.

Caution:

If you configure an alternate journaling mailbox, you must monitor the mailbox to make sure that it does not become unavailable. If the alternate journaling mailbox becomes unavailable and rejects journal reports, the rejected journal reports are lost and cannot be retrieved. Remember this when you decide whether to use an alternate journaling mailbox and how to configure the alternate journaling mailbox.

Only journal reports that are submitted for delivery to an unavailable journaling mailbox after an alternate journaling mailbox is configured will be redirected to the alternate journaling mailbox. Journal reports that have already failed delivery when an alternate journaling mailbox is enabled are not redirected.

If you configure an alternate journaling mailbox, you can reduce the load on your Hub Transport servers and Mailbox servers. Exchange will not continually try to deliver the journal reports to an unavailable journal mailbox. Instead, Exchange will redirect the journal reports to the alternate journal mailbox where the journal reports can remain until you are ready to resubmit them to the journal mailbox.

However, because the alternate journaling mailbox collects all the rejected journal reports for the whole Exchange 2007 organization, you must make sure that this doesn't violate any laws or regulations that apply to your organization. If laws or regulations prohibit your organization from allowing journal reports sent to different journaling mailboxes from being stored in the same alternate journaling mailbox, you may be unable to configure an alternate journaling mailbox. Discuss this with your legal representatives to determine whether you can use an alternate journaling mailbox.

When you create the alternate journal mailbox, you should use the same criteria that you used when you created the journal mailbox. You must make sure that the following conditions are true:

• Only those individuals who are authorized to access the mailbox are given access to the mailbox.
  
  
• You provide a storage quota that meets the needs of your data, hardware, and disaster recovery needs.
  
  
• Only authorized accounts can submit journal reports.
  
  

Remember that because the alternate journaling mailbox accepts rejected journal reports for all journal mailboxes in your Exchange 2007 organization, the hardware resource requirements and mailbox storage quotas may be significantly larger than those that are required for a journal mailbox.

For more information about how to configure an alternate journal mailbox, see How to Configure an Alternate Journaling Mailbox.