Error while dynamically loading mapi32.dll

Our application uses Simple MAPI to send e-mails. One of our clients has problems sending e-mail from a session on his terminal server.

The mapi32.dll is loaded with a call to LoadLibrary which succeeds, but then our application tries to get the addresses of the functions MAPILogon, MAPILogOff, MAPISendMail, MAPIFreeBuffer and MAPIResolveName. The problem is that GetProcAddress fails for those functions with an ERROR_ACCESS_DENIED (code: 5) except for MAPIFreeBuffer. It looks like some sort of security thing.

How can I fix this or should I use another method to send mail?

FWI, here some more information about OS and contents of registry key HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows Messaging Subsystem:

OS info: 5.2.3790 VER_PLATFORM_WIN32_NT Service Pack 2

Contents of SOFTWARE\Microsoft\Windows Messaging Subsystem
InstallCmd: rundll32 setupapi,InstallHinfSection MSMAIL 132 msmail.inf
MAPI: 1
CMCDLLNAME: mapi.dll
CMCDLLNAME32: mapi32.dll
CMC: 1
MAPIX: 1
MAPIXVER: 1.0.0.1
OLEMessaging: 1
Contents of SOFTWARE\Microsoft\Windows Messaging Subsystem\MSMapiApps
inetsw95.exe: 
choosusr.dll: 
msab32.dll:
nwab32.dll:
outstore.dll: Microsoft Outlook
CDOEXM.DLL:
EMSMDB32.DLL:
EMSABP32.DLL:
newprof.exe: Microsoft Outlook
outlook.exe: 
wfxmsrvr.exe: Microsoft Outlook
msexcimc.exe:
exchng32.exe:
schdmapi.dll: Microsoft Outlook
pilotcfg.exe: Microsoft Outlook
mailmig.exe: Microsoft Outlook
admin.exe:
msspc32.dll: Microsoft Outlook
cnfnot32.exe: Microsoft Outlook
ilpilot.exe: Microsoft Outlook
events.exe:

I'm on Delphi 7.0, but that shouldn't matter.

Edit, added version information:

Fileversion info of C:\WINDOWS\system32\mapi32.dll

Fileversion: 6.5.7226.0
FileDescription=Extended MAPI 1.0 for Windows NT
CompanyName=Microsoft Corporation
InternalName=MAPI32
Comments=Service Pack 1
LegalCopyRight=Copyright (C) 1986-2003 Microsoft Corp. All rights reserved.
LegalTradeMarks=Microsoft(R) and Windows(R) are registered trademarks of Microsoft Corporation.
OriginalFileName=MAPI32.DLL
ProductName=Microsoft Exchange
ProductVersion=6.5

Fileversion info of C:\Program Files\Common Files\SYSTEM\MSMAPI\1043\msmapi32.dll

Fileversion: 11.0.5601.0
FileDescription=Extended MAPI 1.0 for Windows NT
CompanyName=Microsoft Corporation
InternalName=MAPI32.DLL
LegalCopyRight=Copyright © 1995-2003 Microsoft Corporation. All rights reserved.
OriginalFileName=MAPI32.DLL
ProductName=MAPI32
ProductVersion=11.0.5601

回答1:

I found the problem. As you can see in my question the mapi32.dll is provided by Exchange server. (Version 6.5.7226 = Microsoft Exchange Server 2003 SP1). According to this site Exchange 2003 does not support Simple MAPI for security reasons:

As of Exchange 2003, Exchange no longer implements Simple MAPI. The API was removed to reduce the potential attack surface

So that is the reason I cannot get the ProcAddresses of the Simple MAPI calls.

It looks like I have to go support Extended MAPI.

回答2:

I think it's a problem of mixed versions of mapi32.dll. Such as maybe Office2003 and 2007 on the same machine, or a botched uninstall/re-install crossing versions (i.e. tried to uninstall 2007 and go back to 2003, or vice-versa). Have the client search the entire HD for mapi32.dll and see if there are multiple versions. If there's only one, compare the version to a known, working system.

See this: http://www.techtalkz.com/microsoft-outlook/391309-mapi32-dll-error-help-my-kids-xms-gift-broken.html