After upgrading to Microsoft Exchange Server 2010 Service Pack 1 (SP1), some users no longer receive quota warning messages even though their mailbox size is over the quota warning threshold.
The way quota warning messages are generated in Microsoft Exchange Server 2010 SP1 has changed. Prior to SP1, all mailboxes on a server are checked during the quota warning schedule to see if their size has exceeded the quota warning threshold. If so, a quota warning message is created for that mailbox.
In SP1, a new flag has been introduced that controls whether a mailbox is checked to see whether its size has exceeded the warning threshold. This flag is set on a mailbox if the mailbox size is more than 50% of the Prohibit Send quota.
This means that if the warning quota is set to a value less than 50% of the Prohibit Send quota, it is possible for the mailbox size to be over the warning quota limit but still not over 50% of the Prohibit Send Quota. In this case, the mailbox will not be checked to see if it has exceeded its threshold and will not receive a quota warning message.
In addition, once a mailbox has been checked during the QuotaNotificationSchedule (per database), the flag is cleared. This means the mailbox will not be checked again until the flag is reset. This happens when either a message is saved in the mailbox or a message is submitted. At that , point if the mailbox size is more than 50% of the Prohibit Send quota then the flag is reset and the mailbox will be checked during the next time slice of the QuotaNotificationSchedule.
If quota warning messages are to be generated, set the Quota Warning threshold to more than 50% of the Prohibit Sent limit.
If an administrator needs to see if mailboxes are over Warning, Prohibit Send and Prohibit Send and Receive Storage limits, he can increase diagnostic logging using the following steps:
Open the Exchange Management Console
Expand Microsoft Exchange On-Premises
Choose Server Configuration
Select the the servername under Server Configuration for which you want to increase logging
Choose Manage Diagnostic Logging Properties... under the Actions pane
Expand 900 Private
Choose Storage Limits
Select the Expert radio button and click Configure
There is no need to restart the MSExchangeIS service or dismount and remount the database stores for this setting to take affect.
The next time the QuotaNotificationSchedule is run, events will be logged in the application log detailing mailboxes that have exceeded the Issue Warning storage limit, the Prohibit Send Storage Limit, and Prohibit Send and Receive Storage Limit.
To see the QuotaNotificationSchedule for each database, run: