Managing message size limits in Exchange 2007 using powershell

The lists I have given below show the most common message size limits, however there are some attachment and header limits that the commands may not show you, so follow the links at the bottom of this article for further informationif you still have problems.

NOTE: Always include the qualifier ‘MB’ when using the management shell to specify message size restrictions.

NOTE: http://technet.microsoft.com/en-us/library/bb124345.aspx is the MASTER reference article for size restrictions for Exchange 2007 and most of the information below is plucked from there. The idea of this article is to extract and simplify some of the commands to get and set the settings.

Global Settings

Scope: RTM Only. Transport setting will change this automatically in SP1

Note: If the values found here and the values found using ‘get-transportconfig | fl M*ze’, the lowest value takes precedence.

Global Settings stored in Active Directory (access using ADSIEdit)
Configuration –> Services –> Microsoft Exchange –> [DOMAINNAME] –> Global Settings –> right client
Message Delivery –>
Check the settings below. They are in KB
msExchRecipLimit (default 5000)
submissionContLength (default 10240) (MaxSendSize)
delivContLength (default 10240) (MaxReceiveSize)

Transport Setting

Scope: Organisational limits for ALL EX2003 / EX2007 servers in the entire organisation.

To show current settings:
get-transportconfig | fl M*ze

To Alter:
Set-TransportConfig -MaxRecipientEnvelopeLimit -MaxReceiveSize MB -MaxSendSize MB

Also check there are no Transport Rules to check the Attachment size of messages.

Connector Limits

Scope: Will affect all messages using the specified connector. Either Send,Receive or Foreign.

To retrieve current settings:

get-ReceiveConnector | ft Id*,M*ze
Get-SendConnector | ft Id*, M*ze
Get-ForeignConnector | ft Id*, M*ze

To Alter:

Set-ReceiveConnector “” -MaxMessageSize MB
Set-SendConnector “” -MaxMessageSize MB
Set-ForeignConnector “” -MaxMessageSize MB

‘Server Specific’ Limits and Outlook Web Access (OWA) limits

Scope: Hub/Edge servers with Transport Rule AND Client Access Servers for the OWA restrictions.

Check there are no transport rules that have ‘server specific’ attachment size over restrictions

CAS servers provide OWA for users to access mail using a web browser. The underlying engine is ASP.NET.

ASP.NET uses the maxRequestLength setting to determine the maximum amount of data that the Web browser can submit to the Client Access server
The setting can be found in the web.config file.

See http://technet.microsoft.com/en-us/library/aa996835.aspx for instructions on changes needed here.

‘Multiple Sites’ and ‘E2000 \ E2003 Co-Existence’ Settings

Scope: Will affect messages using the site links and the routing group connectors for delivery. The settings themselves
DO NOT affect least-cost routing decisions.

* Note that Exchange 2007 RTM does not support site link or routing group connector size limits and routing loops
may occur if they are set. SP1 and above does support size limits though.

Active Directory site links:

Get-AdSiteLink | ft Name,M*ze
Set-AdSiteLink “Site link name” -MaxMessageSize MB

Routing Group connectors:

Get-RoutingGroupConnector | ft Name,M*ze
Set-RoutingGroupConnector “Name of routing group connector” -MaxMessageSize MB

‘Users and Groups’ Settings
—————————

Scope: All the above is for Transport level restrictions, but you need to check the MaxMessageSize setting for the user mailbox/contact and
also the groups they may belong to.

Get-Mailbox “name of mailbox user” | fl M*ze
Get-MailUser “name of user” | fl M*ze
Get-MailContact “name of contact” | fl M*ze
Get-DynamicDistributionGroup “name of dynamic dist” | fl M*ze
Get-DistributionGroup “name of dist” | fl M*ze
Get-MailPublicFolder “name of public folder” | fl M*ze

Manually SET a limit (if ‘unlimited’)

Some exchange administrators have reported that the limits indicate ‘unlimited’ in one or more of these location, and once they change to a value (such as 100MB), the problems disappear. If you are unsure, I would recommend setting a limit rather than leaving as ‘unlimited’.
Shaun

References:

http://www.msexchange.org/articles-tutorials/exchange-server-2007/management-administration/exchange-2007-message-size-limits.html - Exchange 2007 Message Size Limits

http://technet.microsoft.com/en-us/library/bb124345.aspx - Managing Message Size Limits

http://technet.microsoft.com/en-us/library/bb310771.aspx - How to Modify Exchange 2003 Global Message Size Limits in Exchange 2007 RTM

http://technet.microsoft.com/en-us/library/bb125223.aspx - Message Routing in a Coexistence Environment

http://technet.microsoft.com/en-us/library/bb738125.aspx - How to Configure Message Size Limits for Internal Routing

http://technet.microsoft.com/en-us/library/aa996835.aspx - How to Manage Maximum Message Size in Outlook Web Access