Is you trial version 64 bit and the one that is not working 32 bit? That can be a problem sometimes.

Or you are trying it on another PC with say a 64bit operating system when the last one was 32bit.

My finding is the operating system, and both applications have to be the same "bitness" either 32 or 64 for mapi to work reliably. But this is just my conjecture.

Thanks Matt for your response.

They (Thunderbird and DKS Auto) weren't the same bitness (good conjecture) - I installed and setup Thunderbird 32-bit but have received the same error code unfortunately.

THIS IS UPDATED _ PLEASE USE THIS INFO

It is likely this is a Microsoft being awkward so the program DKS Auto has decided to include code which means whether you like it or not it will only look for Outlook.

However, I have come across similar cases when a printer will only look for Outlook.

So, you could make it think it's using Outlook, but it's not - sort of trick it, but I need to know if you have the following. As you had Outlook installed it should have created certain registry info.

In Windows search type: Registry and select 'Registry Editor' to open. Do you see both of these:

• HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\outlook.exe
• HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\thunderbird.exe

Post an image which shows me what you see.

If you do see the above..... I am proposing you basically copy the data that in the 'App Paths\thunderbird.exe and put it into the App Paths\outlook.exe

Your DKS Auto software program will look for App Paths\outlook.exe and find it, but it is tricked into using thunderbird - (assuming that it is auto searching for outlook.exe).

You only need to copy and paste two pieces of data from App Paths\thunderbird.exe and put it into the App Paths\outlook.exe. Full instructions below.

Locate:

• HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\thunderbird.exe
• On the right it will have two ab listed names (Default) and 'Path' both of type 'REG_SZ'
• Double click on 'Default' name to open 'Edit String' window.
• Do NOT edit anything.
• Copy all the 'Value Data' - highlight all text, right click and select 'Copy'
• click on 'Cancel' to close as you do not want to save anything.

Locate

• HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\outlook.exe
• Double click on 'Default' name to open 'Edit String' window.
• In the 'Value Data' text box, if it has data - clear it then Paste in the copied text - right click and select paste.
• click on 'OK' to save

Locate:

• HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\thunderbird.exe
• Double click on 'Path' name to allow you to 'Edit String'.
• Do not edit anything.
• Copy all the 'Value Data' - highlight text, right click and select 'Copy'
• click on 'Cancel' to close.

Locate

• HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\outlook.exe
• Double click on 'Path' name to allow you to 'Edit String'.
• REmove all contents and Paste in the copied text - right click and select paste.
• click on 'OK' to save

I tried the above, restarted, then went to print but it still started Outlook unfortunately (when I set it to start Outlook), then when I set the program to use Default Email Program it had the same error message as above.

Thank you very much for your response Todd - it makes a lot of sense and am surprised it didn't work.

You say "then went to print"

Why 'print' ? Print goes to a printer.

You are wanting to attach a file eg: an invoice to an email, so I would expect you to use 'Send to' email type of action.

Are you using DKS Auto when you select to 'Send to' or MS Access ?

Do you still have Outlook installed ? what version of MS Access have you got installed ?

If you have MS Access but uninstalled Outlook' - It is likely that Microsoft removed the MAPI function from Access which is a fair deal since they own it.