I can't figure out this behaviour for the life of me. I was presented with a problem from a customer which I was easily able to duplicate. They have 64-bit Windows 7 running 32-bit Lotus Notes. When they go into Windows Explorer and pick a file, they right-click, choose "Send To - Mail Recipient" and an error message comes up as described in this Microsoft technote (entitled Figure 1) : Building MAPI Applications on 32-Bit and 64-Bit Platforms
(My error message and that of the customer says the same thing, but instead of asking for Outlook, it asks to install an email program)
Since Lotus Notes is a 32-bit client, everything seemed as it should. There was a 64-bit MAPI call being made by the OS which the 32-bit client was unable to respond to, so I had duplicated the reported problem. The Microsoft technote confirmed that this should not work (with the odd exception of using fixmapi.exe).
I had the problem escalated to see if there was anything we could do for this customer, and Level 3 support are unable to duplicate the problem. They are running Win7x64 on a VMWare image. I have verified that L3 are running a 64-bit version in Control Panel - System (OS comes up as Windows 7 Enterprise, and System Type comes up as 64-bit Operating System) and IBM does not make a 64-bit version of Notes. So I am stumped, how could it possibly work for L3? In case anyone wants to try it, you don't specifically need a Notes client, any 32-bit mail client will do.
1). Verify you have a 64-bit Windows 7 install via Start - Control Panel - System. There is an entry entitled "System Type". It needs to say "64-bit Operating System".
2). Next, install a Notes client or any 32-bit mail client.
3). Then, go to Start - Default Programs - Set your Default Programs. Find Lotus Notes Mail in the list, and select "Set this program as default". That will make the 3 elements Notes uses to make Notes your default mail system.
4). Then go to Explorer, pick any file at all, and right-click. Choose "Send To - Mail Recipient". It won't work.
Then to complete the test, install 64-bit Thunderbird and make it the default mail client, and boom, it works. So the question is, how in the world did L3 make this work with a 32-bit Notes client? No one can figure it out, so we can't tell the customer how to make it work.