How to Set the Gateway Out Threads Registry Value

 

The Gateway Out Threads registry value defines the number of threads available for retrieving messages from the information store process (Store.exe) to the MTA process (Emsmta.exe). When messages are received in the MTA from an Exchange 5.5 server, they move from the MTA to the information store process, and then to the advanced queuing engine. Administrators may notice slight performance degradation in Microsoft Exchange 2000 Server and Microsoft Exchange Server 2003 in comparison to Microsoft Exchange Server 5.5, particularly when the Microsoft Exchange Message Transfer Agent (MTA) Stacks service is used to send and receive mail. In environments in which many messages reach the MTA at the same time, it is recommended that you increase the number of processing threads between the Store.exe process and MTA from 1 to 3 for all private databases on the server.

The Gateway Out Threads registry value is typically set concurrently with the Gateway In Threads and Max RPC Calls Outstanding registry values.

For detailed instructions about how to set the Gateway In Threads registry value, see How to Set the Gateway In Threads Registry Value.

For detailed instructions about how to set the Max RPC Calls Outstanding registry value, see How to Set the Max RPC Calls Outstanding Registry Value.

Before You Begin

Before you perform the procedure in this topic, be aware of the following information:

• Each thread consumes about 1 MB of virtual memory. Additionally, the actual number of threads created is this value multiplied by the number of databases. This may be an issue on servers with many private databases. For example, if you have 10 private databases, and you increase this parameter and the following parameter from 1 to 3 (a total increase of 4 threads), you actually creates 4 x 10 = 40 threads, which together consume 40 MB of virtual memory.

• This topic contains information about editing the registry.

  Warning

  Incorrectly editing the registry can cause serious problems that may require you to reinstall your operating system. Problems resulting from editing the registry incorrectly may not be able to be resolved. Before editing the registry, back up any valuable data.

Procedure

To set the Gateway Out Threads registry value

1. Open a registry editor, such as Regedit.exe or Regedt32.exe.

2. Navigate to HKLM\System\CurrentControlSet\Services\MSExchangeIS\<ServerName>\Private-<GUID>.

3. Right-click Private-<GUID> and click New | DWORD Value.

4. Name the value Gateway Out Threads.

5. Double-click Gateway Out Threads.

6. In the Value data field, enter the appropriate value for your organization and click OK.

7. Repeat steps 3 to 6 for each private information store on the server. That is, if there are two private information stores on the server, there will be two Private-<GUID> keys in the registry.

8. Exit the registry editor and restart the Microsoft Exchange Information Store service for the change to take effect.

For More Information

• For information about MTA tuning in Exchange Server 5.5 organizations that coexist with Exchange 2000 Server or Exchange Server 2003, see Microsoft Knowledge Base article 264075, "Description of MTA tuning when Exchange 5.5 coexists with Exchange 2000 Server or with Exchange Server 2003," (https://go.microsoft.com/fwlink/?LinkId=3052&kbid=264075).

• For information about how to edit the registry, see Microsoft Knowledge Base article 256986, "Description of the Microsoft Windows Registry" (https://go.microsoft.com/fwlink/?linkid=3052&kbid=256986).