Exchange 2007 Message Size Limits
In my previous article I showed you how to set message size limits in Exchange Server 2003. Exchange Server 2007 is somewhat different. I will try to show you where you can limit the message size.
It is possible to set size limits for messages in your Exchange organization on several objects in the Exchange Management Console or with the Exchange Management Shell. This article will show you where you can set these limits and how they interact.
Scope of Limits
It is possible to apply message size filters on different areas in Exchange Server 2007. The limits that you apply at Organization level, apply to all Exchange Servers 2007 in your Exchange organization and you will need appropriate permissions to set limits. If you deployed more than one Hub Transport Server (HTS) than all these limits apply to all Hub Transport Servers. If you are using the Exchange Edge Transport Server (ETS), message size limits apply to the specific Exchange Edge Server.
Global limits are used when you have a mixed Exchange Server 2003 / 2007 environment. Global settings apply to all Exchange Servers 2003 and 2007 because these Message size limits are stored in Active Directory. These global settings are equivalent to the global settings section in the Exchange Server 2003 System Manager. When the settings on the Organizational level conflict with the Global limits the lowest setting takes precedence.
One can also define message size limits on Exchange Server 2007 Connectors. Exchange Server 2007 uses send connectors; receive connectors and foreign connectors to enable interoperability with “Standard” or Legacy messaging systems. Message size limits for connectors are bound to the specific Exchange Edge Transport or Hub Transport Server.
Another way to apply message size limits is to set specific limits at Server level. Limits that you define here are applied to the specific Exchange Hub Transport Server or Edge Transport Server because message limits are not stored in Active Directory.
The last place where it is possible to apply message size limits are on objects like Mailboxes, Mail Users, Mail contacts, Public folders and distribution groups.
For most configuration settings, we will use the Exchange Management Shell (EMS). This is the prefered method for setting message size limits.
Should you wish to see the global settings for the Exchange Transport configuration, use the Exchange Management Shell CMDLet GET-TRANSPORTCONFIG.
Figure 1: GET-TRANSPORTCONFIG
Should you wish to change message size settings you must use the CMDLet SET-TRANSPORTCONFIG. To change the maximum message size for Receive messages, use the following CMDLet:
Figure 2: SET-TRANSPORTCONFIG
Should you wish to set a maximum message size for messages sent to users outside the Exchange organization, use the following CMDLet:
As mentioned above, it is also possible to set message size limits for Exchange Server 2007 Send Connectors, receive Connectors and Foreign Connectors.
Should you wish to see the number of Exchange Receive connectors, use the following CMDLet:
Get-receiveconnector | List
Figure 3: GET-RECEIVECONNECTOR
Should you wish to see the configuration of Exchange Send connectors, use the following CMDLet:
Get-sendconnector | List
Figure 4: GET-SENDCONNECTOR
Should you wish to change the message size limit for a connector, use the following CMDLet:
SET-SENDCONNECTOR –IDENTITY RAUS –MaxMessageSize MessageSizeYouWant
You must use the –IDENTITY parameter only if there is more than one send connector on the server.
One can also set several message size limits directly on the Server.
The CMDLet: GET-TRANSPORTSERVER | LIST displays all settings on the specific Transport Server.
Figure 5: GET-TRANSPORTSERVER
Shoudl you wish to change some settings for the Transport Server you must use the CMDLet SET-TRANSPORTSERVER and the required switches and parameters.
Exchange Server 2007 can apply several message size limits on the following objects:
- Distribution Group
It is possible to set message size limits on every Exchange Mailbox. The following CMDLet GET-Mailbox shows all mailboxes from the specific Mailbox server.
The CMDLet GET-Mailbox –identity Janas | List show the mailbox details and the MaxSendSize and the MaxReceiveSize.
Figure 6: GET-MAILBOX
Should you wish to change settings for the mailbox use the following CMDLet:
SET-Mailbox –Identity Janas –MaxSendSize 1038400
With the help of piping it is possible to change specific settings for all or a selected number of mailboxes.
You can use the same procedure to display the settings for mail contacts or to change some settings related to message sizes.
Get-MailContact –Identity SiminAnton | List
Figure 7: GET-MAILCONTACT
Should you wish to change settings use the CMDLet:
Set-Mailcontact –Identity SiminAnton –MaxSendSize 10240000
Should you wish to change the message size limits for public folders, you must use the Exchange System Manager from Exchange Server 2003 or the Exchange Management Shell (EMS). With Exchange Server 2007 SP1 it will be possible to manage public folders with the Exchange Management console. As of writing this tutorial, Exchange Server 2007 SP1 is still in beta, so we use the EMS and the following CMDLet:
Get-MailPublicFolder –Identity MSExchange | List
This CMDLet displays all the settings for the public folder called MSExchange. If you want to change settings use the CMDLet, Set-MailPublicFolder –Identity MSExchange
Public Folder size limits with Exchange Server 2007 SP1 (Beta)
Here is a preview on the upcoming Exchange Server 2007 SP1. With the help of SP1 you have a public folder console in the Exchange toolbox which is dedicated for public folder management.
Figure 8: Public Folder limits in Exchange Server 2007 SP1 (Beta)
It is possible to set message size limits on distribution groups with the EMC and EMS. The following picture shows the EMC to set message size limits.
Figure 9: Message size limits for a Distribution group
You can use the GUI (EMC) or the EMS to set message size limits for distribution groups. If you want to use the EMS, use the following CMDLet:
Get-DistributionGroup –Identity Telta | List – Displays the settings for the Distribution group named Telta.
Figure 10: Message size limits for a distribution group
Should you wish to change some settings use the CMDLet:
Set-DistributionGroup –Identity Telta –MaxReceiveSize 10240000
Differences between Exchange Server 2003 and 2007
Exchange Server 2007 handles message size limits to distribution list recipients differently. Exchange Server 2003 distribution list members treat each member of the distribution group as an individual member so it was possible that some members would not receive any messages due to message size limits. To avoid this possible problem, Exchange Server 2007 handles all members of a distribution list as one member, so message size restrictions can be better controlled.
It is possible to set size limits on several objects in Exchange Server 2007. You should know where to set these limits and how they interact. This article does not explain all the locations where one can set message size limits but this should be enough for most purposes.