Limiting the number of recipients of a message

MORE INFORMATION

Warning Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. These problems might require that you reinstall your operating system. Microsoft cannot guarantee that these problems can be solved. Modify the registry at your own risk.
To set this parameter, perform the following steps:

1. Start Registry Editor (Regedt32.exe).
2. Locate the following key in the registry:

   HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MSExchangeIS\ ParametersSystem

   Note The above registry key is one path; it has been wrapped for readability.
3. On the Edit menu, click Add Value, and then add the following registry value:

   Value Name: Max Recipients on Submit
   Data Type: REG_DWORD
   String: A value equal to the maximum number of recipients that you want to allow

4. Quit Registry Editor.

In Exchange Server 5.5 and earlier, this limit also applies to messages that are transferred into the store by the Internet Mail Service. An event ID 4117 message is logged and the message is moved to the Archive folder. The message is not delivered and it does not send a non-delivery report (NDR).

Note In Exchange 2000 and later, only messages submitted with MAPI are subject to this restriction. To configure recipient limits that work for all messages regardless of how they are submitted, use the setting that is located under Global Settings\Message Delivery in Exchange System Manager.

If a user attempts to send a message to more recipients than is designated by the Max Recipients on Submit parameter and the user has the new Emsmdb(32).dll, the following error message may be displayed when the user attempts to send the message: If a user attempts to send a message to more recipients than is designated by the Max Recipients on Submit parameter and the user DOES NOT have the new Emsmdb(32).dll, the following error message may be displayed when the user attempts to send the message: Note the following when you add the above registry key:

• You do not have to stop and restart services for this change to take effect.
• The number you choose applies to total recipients associated with a message (To+Cc+Bcc=Total).
• You cannot circumvent the limit by using a personal distribution list; it is evaluated for number of entries before the send.
• In Exchange Server 5.5 only, server-based distribution lists let you exceed the total number of recipients. You can do this by using the Max Recipients on Submit registry value if you have the correct permissions.

Note The new Emsmdb32.dll file referenced in this article is included in Exchange Server 4.0 SP2 and all later versions of Exchange Server.