Microsoft TechNet says:
SYMPTOMS
========
When you use a Microsoft Office 97 application such as Microsoft Word or
Microsoft Excel and click Send To on the File menu, and then click Mail
Recipient, you may get the following error message:
Word couldn't send mail because of MAPI failure: "Unspecified Error".
RESOLUTION
==========
To resolve this problem, modify the following registry entry.
WARNING: Using Registry Editor incorrectly can cause serious problems that may
require you to reinstall your operating system. Microsoft cannot guarantee that
problems resulting from the incorrect use of Registry Editor can be solved. Use
Registry Editor at your own risk.
For information about how to edit the registry, view the "Changing Keys and
Values" Help topic in Registry Editor (Regedit.exe) or the "Add and Delete
Information in the Registry" and "Edit Registry Data" Help topics in
Regedt32.exe. Note that you should back up the registry before you edit it. If
you are running Windows NT or Windows 2000, you should also update your
Emergency Repair Disk (ERD).
HKEY_CURRENT_USER/Software/Microsoft/Windows NT/Current Version/Windows
Messaging Subsystem/Simple MAPI- CMC/SendNoteUI = 1
The default value is zero. Setting the value to one allows you to send mail from
Office 97 applications using Outlook 97.
Hope this helps
mscallisto