Starting in Strategy 9.3.1, additional logging is available for Distribution Services. The "Delivery Details" trace is useful when trying to determine details regarding a specific subscription execution. It can be found in the Strategy Diagnostics and Performance Logging tool as shown below:

Note: This log is not enabled by default. An existing or new "File Log" destination must be selected for this logging to be used.
When a subscription runs on a schedule or the "Send Now" feature is utilized, a subsequent job will be created for Distribution Services. This trace will display details about subscriptions that were triggered and the subscription recipients. The following entries are seen in the trace when a subscription is triggered:
2013-11-30 19:52:09.401-05:00 MSIDeliveryEngine::DeliveryTransmission(): lDeliveryType= 1.<Subscription 'Customer Income Analysis 11/30/13 7:51:35 PM' (ID = EFDADFD447358B6838AF8FB1BF46FAF0), Contact 'Administrator' (ID = 54F3D26011D2896560009A8E67019608) >
2013-11-30 19:52:09.432-05:00 MSIDeliveryEngine::hGetDeliveryAddresses(): lErrorCode = 0 lDeliveryType = 1 lIsPushNotificationEnabled = true.<Subscription 'Customer Income Analysis 11/30/13 7:51:35 PM' (ID = EFDADFD447358B6838AF8FB1BF46FAF0), Contact 'Administrator' (ID = 54F3D26011D2896560009A8E67019608) >
2013-11-30 19:52:09.447-05:00 MSIDeliveryEngine::hDelivery(): there are 1 addresses and lEmailAddressFailure = with iNotification = false.<Subscription 'Customer Income Analysis 11/30/13 7:51:35 PM' (ID = EFDADFD447358B6838AF8FB1BF46FAF0), Contact 'Administrator' (ID = 54F3D26011D2896560009A8E67019608) >
2013-11-30 19:52:09.479-05:00 Distribution Services TransformationSettings: EndDelimiter***BeginDelimiter++++***FileFormat++++4***export_settings++++<extendable_parameter><export_options ef="4" vm="1"><export_mode>1</export_mode></export_options></extendable_parameter>***IncludeData++++1***Subject++++Customer Income Analysis***fileName++++Customer Income Analysis***SendToHistory++++0***ReuseHL++++0***IncludeLink++++0***zip++++0***ProtectZipFile++++0***ContactCollectionMode++++0***stid++++0***expiration_date++++ ***
2013-11-30 19:52:09.494-05:00 MSIDeliveryEngine::hDelivery(): bIsReport = true bIsBulkExport = false bIsDocument = false bIsRWDoc = false bIsHTMLDoc = false.<Subscription 'Customer Income Analysis 11/30/13 7:51:35 PM' (ID = EFDADFD447358B6838AF8FB1BF46FAF0), Contact 'Administrator' (ID = 54F3D26011D2896560009A8E67019608) >
2013-11-30 19:52:09.510-05:00 MSIDeliveryEngine::hDelivery(): bDeliverOnParialResult = false bIncludeData= true bIsBursting= false bUseSeperateAddressReport = false.<Subscription 'Customer Income Analysis 11/30/13 7:51:35 PM' (ID = EFDADFD447358B6838AF8FB1BF46FAF0), Contact 'Administrator' (ID = 54F3D26011D2896560009A8E67019608) >
2013-11-30 19:52:09.541-05:00 MSIDeliveryEngine::hDelivery(), there are 1 addresses to delivery. <Subscription 'Customer Income Analysis 11/30/13 7:51:35 PM' (ID = EFDADFD447358B6838AF8FB1BF46FAF0), Contact 'Administrator' (ID = 54F3D26011D2896560009A8E67019608) >
2013-11-30 19:52:09.557-05:00 Distribution Services DeliverySettings: EndDelimiter***BeginDelimiter++++***FromDisplayAddress++++Strategy Distribution Services***FromPhysicalAddress++++DistributionServices@Strategy.com***ReplyDisplayAddress++++Strategy Distribution Services***ReplyPhysicalAddress++++DistributionServices@Strategy.com***SendOption++++SendOptionSend***DeliveryStatusNotificationDSN_TYPE++++DSN_TYPE_NONE***FORMAT++++FORMAT_MIME***UseSmartHostAlways++++false***SmartHostAddressPort++++25***HTMLTextBodyEncoder++++quoted-printable***TextAttachmentEncoder++++quoted-printable***BinaryAttachmentEncoder++++Base64***PUT_QUOTES_AROUND_DISPLAY_NAMES++++PUT_QUOTES_AROUND_DISPLAY_NAMES_YES***UseASCIINamesOnly++++true***HTMLEmbedAttachments++++DoNotEmbed***ContentEncoder++++quoted-printable***REPORT_DOC_NAME++++Customer Income Analysis***DESTINATION++++DESTINATION_TO***RECIPIENT_NAME++++Administrator***.<Subscription 'Customer Income Analysis 11/30/13 7:51:35 PM' (ID = EFDADFD447358B6838AF8FB1BF46FAF0), Contact 'Administrator' (ID = 54F3D26011D2896560009A8E67019608) >
2013-11-30 19:52:09.588-05:00 GetHTMLDataAndImages() there are 0 graphs
2013-11-30 19:52:09.603-05:00 Distribution Service: lRecipientAddressName: 'support@Strategy.com' lRecipientPhysicalAddress: support@Strategy.com.<Subscription 'Customer Income Analysis 11/30/13 7:51:35 PM' (ID = EFDADFD447358B6838AF8FB1BF46FAF0), Contact 'Administrator' (ID = 54F3D26011D2896560009A8E67019608) >