Exchange 2007 – Recipient Limits

Recipient Limits

There are several ways to establish recipient limits within Exchange 2007.

· Organization Limits

· Global Limits

· Connector Limits

· Server Limits

· User Limits

Organization Limits: Apply to all Exchange 2007 Servers within the Organization.

Global Limits: Apply to all Exchange 2007 and Exchange 2003 servers that exist in the Organization.

Connector Limits: These limits apply to any messages that use the specified Send connector, Receive connector, or Foreign connector for message delivery.

Server Limits: These limits apply to a specific Hub Transport or Edge Server.

User Limits: These limits apply to a specific user object such as a contact, mailbox, distribution group, public folder.

 

Recipient Limit Recommendations

Generally, it is better to maximize the restrictiveness of your message limits. You should base any exceptions on a proven need to exceed the established size limits, and you should put those limits as close as possible to the objects that must exceed the established limits. This strategy helps make sure that messages in the transport pipeline are rejected as early as possible if they violate message size limits. It is a waste of system resources to set a high message size limit at the Exchange organization level, allow a message to enter the Exchange organization, and then reject the message at the last stage of delivery because of a violation of a message limit.

Scenario: Recipient Limit Requirements

Note:  The information below is a stripped list of recipient limit Q&A taken from a real customer.  Recommendations are based on these requirements, and as in the real world.. not all of the requirements can be fulfilled out of the box with Exchange or may go against best practice for setting limits. 

• Only select users can send to All the Organization? Yes
• Restrict Certain Distribution Groups to only allow particular users to send to them (ex. All Users)? YES
• Maximum Recipient limit for Messages Sent within the Exchange Organization (Exchange to Exchange): 500
• Maximum Recipient limit for Messages Sent to the Internet? 500
• Maximum Recipient limit for Messages Sent to Domino? 500
• Maximum Recipient limit for Messages Received from Internet? Presently All Inbound mail flows through Domino to Exchange so the Recipient Limit from Domino would apply.
• Maximum Recipient limit for Messages Received from Domino? No Limit

Recommended Recipient Limit configuration based on requirements defined by scenario above.

• Set Receive Connector From Domino and Internet (Same Connector): Unlimited

WARNING: Mail from the Internet and Domino come through the same connector so no limit will be placed on Inbound Internet Mail. Recommendation would be to set this limit the same as the Exchange Organization limit or lower. If internal Exchange users cannot send to more than 500 users then email between the two messaging environments should adhere to the same limitations.

• Set Organization: 500
• Set Limits on who can send to Heavily Populated Distribution Groups (over Org Limit)
• Even if the Organization Restriction is set to 500 and a Groups has 500+ members, the user/group granted the ability to send to this group will still be able to send to all members.

Setting Recipient Limits

This section will provide instruction to setting recipient limits at the Organization, Global, Connector, Server and User level.

Note: Exchange Management Shell is the most efficient way to make these changes, so the commands will be displayed below.

IMPORTANT! When setting limits, whether its recipient, message size, etc. make sure the settings do not step on each other at the various levels. Exchange 2007 SP1 was suppose to fix many of the issues of limits defined at the Organization and Global level; however there are instances where these issues are still evident in SP1.

Organization Recipient Limits

Example: Setting Recipient Limit to 3000:

Note: Default Recipient Limit within Exchange SP1 is “5000”.

Set-TransportConfig –MaxRecipientEnvelopeLimit 3000

To verify settings run the following command:

Get-TransportConfig | fl MaxRecipientEnvelopeLimit

 

Global Recipient Limits

In Exchange 2007 SP1, you shouldn't modify the global limits directly. In Exchange 2007 SP1, if you set a global limit to a different value than the corresponding organizational limit, you will generate event log errors. When you want to modify the organizational limits or the global limits in Exchange 2007 SP1, you should use the Set-TransportConfig cmdlet in the Exchange Management Shell or the Hub Transport organization configuration properties in the Exchange Management Console.

Conditions That Affect the Initial Values of Global Limits in Exchange 2007 SP1

The following list describes the conditions that cause the initial values of the global limits to differ from the default values in Exchange 2007 SP1:

The existing numeric values of delivContLength, submissionContLength, or msExchRecipLimit are preserved for the following circumstances:

• The organization was upgraded from Exchange 2007 RTM and the corresponding organizational limit values that are specified by the MaxReceiveSize parameter, the MaxSendSize parameter, or the MaxRecipientEnvelopeLimit parameter on the Set-TransportConfig cmdlet were set to Unlimited.
  
  
  
  
  
  



• The organization was upgraded from Exchange 2003, and a numeric value was specified for Incoming message size, Outgoing message size, or Maximum number of recipients.
  
  
  
  
  



• The values of delivContLength, submissionContLength, or msExchRecipLimit are changed to match the values of the corresponding organizational limits that are specified by the MaxReceiveSize parameter, the MaxSendSize parameter, or the MaxRecipientEnvelopeLimit parameter on the Set-TransportConfig cmdlet when all the following conditions are true:
  
  
  
  
  
  



• The organization was upgraded from Exchange 2007 RTM to Exchange 2007 SP1.
  
  
  
  
  



• A numeric value was specified for delivContLength, submissionContLength, or msExchRecipLimit.
  
  
  
  
  



• A different numeric value was specified for the corresponding organizational limit in the MaxReceiveSize parameter, the MaxSendSize parameter, or the MaxRecipientEnvelopeLimit parameter.
  
  

Connector Recipient Limits

This content is catered to the scenario’s environment so we will only go through the modifications for the Receive Connectors.

Ex. To set one Receive Connector at a time (ex. Set a connector named “From Domino” and a <server> to maximum of 1000 recipients):

Set-ReceiveConnector –identity “<server>\From Domino” –MaxRecipientsPerMessage 1000

Ex. To set ALL Receive Connectors at One Time:

Get-ReceiveConnector | Set-ReceiveConnector –MaxRecipientsPerMessage 1000

 

Set Server Recipient Limits

This section will provide instruction to setting recipient limits at the Server level.

Note: These limits are applied to a Hub Transporter server

Ex. To Set Hub Transport Server Recipient Limit on a specific HT server to 1000.

Set-TransportServer –Identity <serverName> -PickupDirectoryMaxRecipientsPerPage 1000

Ex. To Set ALL Hub Transport Servers to Recipient limit of 1000.

Get-TransportServer | Set-TransportServer –PickupDirectoryMaxRecipientsPerPage 1000

 

Setting User Recipient Limits

This section will provide instruction to setting recipient limits at the Server level.

Ex. Apply Recipient Limits to a Mailbox.

Set-Mailbox –Identity <mbxUserA> -RecipientLimits 400

Ex. Apply Recipient Limits to a Contact

Set-MailContact –Identity <mContactA> -MaxRecipientsPerMessage 400

Ex. Apply Recipient Limits to a Mail-User

Set-MailUser –Identity <mUserA> -RecipientLimits 400