Recipe5.24.Limiting the Number of Recipients to Which Messages Can Be Sent

Recipe 5.24. Limiting the Number of Recipients to Which Messages Can Be Sent

Problem

You want to control the number of recipients to which a single message can be sent.

Solution

Using a graphical user interface

To set the maximum recipient count globally, do the following:

1. Open the Exchange System Manager (Exchange System Manager.msc).

2. Browse to the Global Settings object and expand the object.

3. Right-click Message Delivery and select Properties from the drop-down list.

4. Select the Defaults tab.

5. In the Recipient limits area, select Maximum (recipients) and enter 100 (or an appropriate value for your organization). Click Apply, and then click OK.

To set it on a per-server basis, do the following:

1. Open the Exchange System Manager (Exchange System Manager.msc).

2. Browse to the Server object (Administrative Groups Administrative Group Name Servers Server Name) and expand the object.

3. Right-click Default SMTP Virtual Server and select Properties from the drop-down list.

4. Select the Messages tab.

5. Limit number of recipients per message to should be set to its default value of 64000. Change this to 100 (or an appropriate value for your organization). Click Apply, and then click OK.

6. Repeat this action for each SMTP virtual server or connector within your organization that you wish this setting to apply to.

Using a command-line interface

Save the following LDF file and run the command ldifde -i -f <filename>.ldf:

# ----------------   limit-recips.ldf ------------------ dn: CN=Message Delivery,CN=Global Settings,CN=<yourOrgName>,CN=Microsoft Exchange,      CN=Services,CN=Configuration, <ForestRootDN> changetype: modify replace: msExchRecipLimit msExchRecipLimit: 100

Using VBScript

' This code sets a cap on the number of recipients allowed  ' on a single message ' ------ SCRIPT CONFIGURATION ------ strMessageDeliveryDN = "cn=message delivery,cn=global settings," & _      "cn=<orgName>,cn=microsoft exchange,cn=services," & _      "cn=configuration, <ForestRootDN>" ' ------ END CONFIGURATION ------ set objMessageLimit = Getobject("LDAP://" & strMessageDeliveryDN) objMessageLimit.Put "msExchRecipLimit", "100" objMessageLimit.SetInfo WScript.Echo "Set recipient limit on " & strMessageDeliveryDN & " to 100"

Discussion

Limiting the number of recipients that can be included in one message can help prevent the spread of viruses by SMTP. We chose to set the recipient limit to 100 per message, but we're not working in an organization where messages are sent to hundreds of recipients at once. While limiting the number of recipients a message can be sent to is a good thing, you should ensure you're not preventing your users from doing business efficiently.

See Also

Recipe 4.10 for more on setting default send and receive limits; MS KB 821881 (How to Modify Global Settings in Exchange System Manager) and MS KB 319356 (How to prevent unsolicited commercial email in Exchange 2000 Server)