XCON: Message Transfer Agent Service Does Not Start Due to Event ID 3047 (271568)

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256986 Description of the Microsoft Windows Registry

SYMPTOMS

When you attempt to start the Microsoft Exchange Server Message Transfer Agent (MTA) service, the following Event IDs may appear in the application event log:

Event ID: 3047
Source: MSExchangeMTA
Type: Error
Category: Configuration
Description:
Unable to initialize due to a bad configuration. Too many threads were requested. The maximum number is xx, and xxx were requested. Contact Microsoft Technical Support. [XAPI MAIN BASE 1] (16)

Event ID: 9406
Source: MSExchangeMTA
Type: Warning
Category: Resource
Description:
There is not enough Performance Monitor memory to display the MTA Connections information. Stop attached Performance Monitors and re-start the MTA. [BASE MAIN BASE 1] (14)

CAUSE

The MTA does not start due to one or more improperly configured registry keys. Too many threads are being requested, which does not allow the MTA to start. The summation of the Decimal value of 4 XAPI thread registry keys plus 3 determines the total number of threads. This total cannot exceed 75. The following Decimal value of these registry keys are summed:

XAPI MA queue threads : REG_DWORD
XAPI MA threads : REG_DWORD
XAPI MT queue threads : REG_DWORD
XAPI MT threads : REG_DWORD

RESOLUTION

WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.

Stop the Message Transfer Agent (MTA) service.
Run Regedt32.exe. To do so, click Start, click Run, and then type Regedt32.exe in the Open: box.
Go to the following subkey:
KEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeMTA\Parameters
Change the Decimal value of the these registry keys (Note: These new values are the default values):
2 for XAPI MA queue threads : REG_DWORD : 0x2
2 for XAPI MA threads : REG_DWORD : 0x2
1 for XAPI MT queue threads : REG_DWORD : 0x1
1 for XAPI MT threads : REG_DWORD : 0x1
Close the Registry Editor, and then start the Message Transfer Agent (MTA).

MORE INFORMATION

The path of the following registry keys is:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeMTA\Parameters

- XAPI MA queue threads

REG_DWORD
0x2
This value is the number of threads that handle interaction with the MTA on behalf of the following clients:
- MDB and XAPI MA Delivery Queue clients.
- XAPI MA Retrieval Queue clients.

- XAPI MA threads

REG_DWORD
0x2
This value is the number of threads that handle calls from the following clients:
- MDB and XAPI MA Delivery Queue clients.
- XAPI MA Retrieval Queue clients.

- XAPI MT queue threads

REG_DWORD
0x1
This value is the number of threads that handle interaction with the MTA on behalf of XAPI MT Gateway clients.

- XAPI MT threads

REG_DWORD
0x1
This value is the number of threads that handle calls from XAPI MT Gateway clients.

- XAPI/MMI client DMOD threads

REG_DWORD
0xa
This value is the maximum number of MTA DMOD threads to handle connections to the following clients:
- MDB and XAPI MA Delivery Queue clients.
- XAPI MA Retrieval Queue clients.
- XAPI MT Gateway clients.
- MMI clients.

All MTA DMOD threads (of whatever type) can support multiple connections. Connections are load-shared over threads of the same type.