Exchange Journaling Mailbox Recommendations

How many journaling mailboxes should I create in my Exchange system; and, are there any size limitations for the mailbox itself?

According to a Microsoft technician, they recommend at least 1 journaling mailbox per mail server.  Exchange can only effectively support mailboxes under 5 - 10G. Exchange will begin to suffer from performance issues when the Inbox begins to exceed 2500-5000 messages.

This means that, once you enable a journaling mailbox, you should begin archiving its contents and using the Retain option to delete the items from the mailbox once archived.

However, if there are delays in getting those journaling mailboxes archived, you should watch the size.  If it gets to 5G, turn it off and re-route email to another journaling mailbox until you get all of them archived and emptied out.

Journaling jobs should have their own Profile with the Scope set to "All messages (ignore date)" and Duplicate Check set to "Try to publish all message (SLOW)" to gather all messages from the beginning of the mailbox. Under Job, "Enable Journaling" and  "Delete archived items from journal" must be enabled (checked) so that the journaling mailbox is cleared during the job, Make sure to also choose the journaling mailbox(es) you want archived.

Important note:

As Retain archives the journal mailbox it creates a list of messages to be deleted but will only send the delete request when it exits the mailbox. If the job fails before it exits then the messages won't be deleted. Limiting the scope of the job to allow Retain to finish the job successfully will ensure that the messages are deleted.

See also:
For Exchange 2010 Create and Configure a Journaling Mailbox
For Exchange 2013 Create and Configure a Journaling Mailbox
Increasing SOAP Timeout Value to Help With Journaling Jobs
Exchange 2010 Powershell Scripts for Transferring Mail From Bloated Journal Mailboxes

This article was originally published in the GWAVA knowledgebase as article ID 2300.