Citrix XenApp 5.0
Windows Server 2008 R1 (64-bit)
Microsoft Office 2003 Professional (32-bit)
When using Outlook 2003 via Citrix session, time zones in Outlook would not match the user session time via Citrix. Email would show the wrong received timestamps.
However if you log on to the same server via Microsoft Remote Desktop (RDP) instead of via Citrix (ICA) the timestamps would be correct.
When going to Options > Calendar Options > Time Zones... Outlook would default to (GMT) Coordinated Universal Time.
We found that registry for AppInit_DLLs registry entries for Citrix was missing. Specifically, the DLL references that provided the necessary hooks for Citrix to provide the time zone redirection of the client session. Since the office application was 32-bit, this meant that the reference for 32-bit applications for these required hooks weren't being applied despite what the Windows Server GPO was instructing or redirecting.
This is the correct setting.
32-bit Application Reference
AppInit_DLLs = c:\progra~2\citrix\system32\mfaphook.dll,mfaphook.dll
64-bit Application Reference
AppInit_DLLs = c:\progra~2\citrix\system32\mfaphook64.dll,mfaphook64.dll