SourceOne DocumentService Issue

I'm working on an implementation of SourceOne Search and another vendor is trying to tie in to the ExDocMgmtSvc/DocumentService.svc using their application.  We are running Lotus Domino on a Windows Server environment.

They are able to connect to the SQL Server to get a list of messages in the Archive to ingest via the DocumentService.svc but are getting various failures depending on the type of Authentication set in IIS
Tests Performed
Test 1:
Actions:
Log in to Search UI in IE9
Search for email - Textbox is "fox"
One email is returned.
Click on email to view in /Search/
Double Click on Email to view in Lotus Notes
Log Activity:
Activity DOES appears in DocManageService log
Activity DOES NOT appear in DocManageWeb log

Test 2:
Actions:
Set IIS Service Authentication to Anonymous Authentication, Windows Authentication, and Basic Authentication
Run a iisreset via cmd line
Log Activity:
Activity DOES NOT appears in DocManageService log
Activity DOES NOT appear in DocManageWeb log
Error on client side:
AuthenticateUser failed on attempt 1 (10 attempts remaining): The request failed with HTTP status 401: Unauthorized.

Test 3:
Actions:
Set IIS Service Authentication to Anonymous Authentication and Windows Authentication OR just Windows Authentication
Run a iisreset via cmd line
Log Activity:
Activity DOES NOT appears in DocManageService log
Activity DOES NOT appear in DocManageWeb log
Error on client side:

HTTP Error 500.0 - System.ServiceModel.ServiceActivationException

Detailed Error Information

Module	IsapiModule
Notification	ExecuteRequestHandler
Handler	svc-ISAPI-2.0
Error Code	0x00000000

Requested URL	http://localhost:80/ExDocMgmtSvc/DocumentService.Svc
Physical Path	E:\Program Files\EMC SourceOne\ExDocMgmt\WebService\DocumentService.Svc
Logon Method	Anonymous
Logon User	Anonymous

Test 4:

Actions:

Set IIS Service to Basic Authentication

Run a iisreset via cmd line

      

Log Activity:

Activity DOES NOT appears in DocManageService log

Activity DOES appear in DocManageWeb log

DocumentService::DoGetMessage|ERROR|GetMessage error: Failed to initialize MAPI. (0x86040C5B) Unspecified error (0x80004005) [DocManageWeb, CoExExchRestore.cpp(63).CoExExchMsg::RestoreMsg2Disk]   |(0)|HE3NTVD477

Errors client receives:

Could not Index Archive\529C6CBFE5690D5152CE1908726A6662B6B32493BD4C67BA00: System.Web.Services.Protocols.SoapException (Failed to initialize MAPI. (0x86040C5B) Unspecified error  (0x80004005) [DocManageWeb, CoExExchRestore.cpp(63).CoExExchMsg::RestoreMsg2Disk]

Is there a basic configuration change that needs to occur so that the other vendor can access the DocumentService.svc or initialize MAPI?  Is the vendor missing a call to an API to initialize the MAPI?  What is the code at CoExExchRestore.cpp line 63 trying to do where it's failing to initialize MAPI?