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MTA

You can increase the level of detail of events written to the application event log by the MTA. In addition, Interoperability and Application Protocol Data Unit (APDU) text logs are triggered by the levels set with diagnostics logging. You can generate these text logs by increasing logging levels.

Use the MTA Diagnostics Logging property page to set or change logging levels and create Interoperability and APDU logs. The MTA on each server has its own Diagnostics Logging property page, so make sure you select the right one.

Getting to the MTA Diagnostics Logging property page

  1. In the Administrator window, select a server.
  2. Double-click Message Transfer Agent.
  3. Select the Diagnostics Logging tab.

Changing MTA Diagnostics Logging Levels

Use the Diagnostics Logging property page to change the logging levels of MTA categories. The application name for the MTA, MSExchangeMTA, is listed in the Services column. All events are logged under this name in the Windows NT application event log. The categories listed in the MTA Diagnostics Logging property page match the categories of events shown in the application event log.

For more information, see "Changing the Diagnostics Logging Level" earlier in this chapter.

Creating Interoperability Logs

Use the diagnostics logging levels in the Interface and Interoperability categories to create Interoperability logs. These text logs consist of the binary contents of X.400 protocol messages transported by the MTA.

Interoperability logs are text files stored in the Mtadata directory. The current log is always named Ap0.log. Old logs are named Apx.log with the x increasing with the age of the log.

Interoperability logs are created when the logging levels in both the Interface and Interoperability categories are set to Medium or Maximum.

Diagnostic logging levels for the Interface category also determine the detail of Interface events sent to the event log. Event logging is not affected by the logging level of the Interoperability category. It determines only whether Interoperability text logs are created.

Interoperability logs can be instrumental in tracking down configuration problems on MTAs. However, they are valuable only to those familiar with ASCII translations of X.400 protocol. These logs can grow large very quickly and affect server performance.

  1. Select the Diagnostics Logging tab.
  2. Select the Interoperability category.
  3. Select Medium or Maximum.
  4. Select the Interface category.
  5. Select Medium or Maximum.

Creating APDU Logs

Use the diagnostics logging levels of the X.400 service and APDU categories to trigger the creation of APDU logs. APDU logs are binary representations of communication among MTAs in different sites and between MTA and client applications within a site. They include the fully encoded Asn.1 envelope.

These text logs are stored in the Mtadata directory. The current log is always named Bf0.log. Old logs are named Bfx.log with the x increasing with the age of the log.

APDU logs are enabled when the logging levels of the X.400 service and APDU categories are both set to Medium or Maximum. There is no difference between Medium and Maximum for the APDU category. However, in addition to its influence on APDU logs, the diagnostics logging level of the X.400 service category determines which X.400 events are written to the Windows NT application event log.

Once enabled, APDU logs are written when any of the following events occurs.

Event # Description Logging Level
200 Bad APDU transferred in from another MTA Minimum
220 Bad APDU submitted to this MTA Minimum
269 APDU delivery failed temporarily Minimum
270 APDU delivery failed permanently Minimum
271 APDU sent Medium
271 APDU received Medium

If the logging levels of both the X.400 service and APDU are set to Minimum or Maximum, the first four events will be written to the event log. If the logging levels of both categories are set to Medium or Maxium, all six events will be logged and the APDU text logs will be written.

APDU logs can be instrumental in diagnosing problems with the MTA. However, they are valuable only to those familiar with ASCII translations of X.400 protocol. These logs can grow large very quickly and affect server performance.

  1. Select the Diagnostics Logging tab.
  2. Select the APDU category.
  3. Select Medium or Maximum.
  4. Select the X.400 Service category.
  5. Select Medium or Maximum.