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Mailbox store prohibit send and receive limits are too similar

[This topic is intended to address a specific issue called out by the Exchange Server Analyzer Tool. You should apply it only to systems that have had the Exchange Server Analyzer Tool run against them and are experiencing that specific issue. The Exchange Server Analyzer Tool, available as a free download, remotely collects configuration data from each server in the topology and automatically analyzes the data. The resulting report details important configuration issues, potential problems, and nondefault product settings. By following these recommendations, you can achieve better performance, scalability, reliability, and uptime. For more information about the tool or to download the latest versions, see "Microsoft Exchange Analyzers" at https://go.microsoft.com/fwlink/?linkid=34707.]  

Topic Last Modified: 2011-05-22

The Microsoft Exchange Best Practices Analyzer Tool queries the Active Directory directory service to determine the mailbox size limits set on a mailbox. If the Exchange Server Analyzer finds that the difference between the Prohibit send and Prohibit send and receive mailbox limits is less than 20 percent, the Exchange Server Analyzer displays a Best Practice configuration message.

It is a best practice to separate the Prohibit send and Prohibit send and receive limits by at least 20 percent. If the difference between the limits is less than 20 percent, the mailbox user may not have enough time to clean-up their mailbox before the mailbox starts to reject messages. For example, if users are prohibited from sending new messages when their mailbox hits 100MB, the Prohibit send and receive limit should be at least 120MB.

Note

It is also important to set a warning limit on the mailboxes. When the mailbox reaches the warning limit, an e-mail message will be sent to the user warning him or her that the mailbox is approaching the limit defined in the Prohibit send limit.

To correct this problem, you should increase the difference between the Prohibit send and Prohibit send and receive mailbox limits to more than 20 percent.

To set mailbox limits

  1. Open the Exchange System Manager.

  2. Locate the mailbox store displayed in the Exchange Server Analyzer message.

  3. Right-click MailboxStore_Name and select Properties.

  4. Select the Limits tab.

  5. Modify the Prohibit send at (KB) limit or the Prohibit send and receive at (KB) limit, or both limits.

  6. Click Apply, and then click OK.

To set mailbox limits on Exchange Server 2007 using the Exchange Management Console

  1. Open the Exchange Management Console.

  2. Locate the mailbox store displayed in the Exchange Server Analyzer regarding this issue.

  3. Right-click MailboxStore_Name and select Properties.

  4. Select the Limits tab.

  5. Modify the Issue warning at (KB), Prohibit send at (KB) limit and the Prohibit send and receive at (KB) limit.

  6. Click Apply, and then click OK.

To set mailbox limits on Exchange Server 2007 using the Exchange Management Shell

  1. The following example shows how to set the mailbox size at which a warning message is sent to the user. This attribute applies to all mailboxes in this mailbox database that do not have their own warning quota attribute set. You must specify either an integer or "unlimited". The default value is 1.9 gigabytes (GB).

    Set-MailboxDatabase "Mailbox Database Name" -IssueWarningQuota 1991680

  2. The following example shows how to set the mailbox size at which users associated with mailboxes in this mailbox database can no longer send messages. This attribute applies to all mailboxes in this mailbox database that do not have their own prohibit send quota attributes set. The limit value set must be either an integer or "unlimited".

    Set-MailboxDatabase "Mailbox Database Name" -ProhibitSendQuota 2097152

  3. The following example shows how to set the mailbox size at which the user associated with this mailbox can no longer send or receive messages. This attribute applies to all mailboxes in this mailbox database that do not have their own prohibit send receive quota attributes set. You must specify either an integer or "unlimited".

    Set-MailboxDatabase "Mailbox Database Name" -ProhibitSendReceiveQuota 2411520

For information about how to set the mailbox limits on Exchange Server 2010, view the topic Configure Storage Quotas for a Mailbox.

For more information about managing Exchange mailboxes, see Working with Exchange Server 2003 Stores.

For more information about managing Exchange mailbox limits in Exchange Server 2007, see How to Configure Database Limits and Properties.