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Multiple version info

  • 3 replies
  • 1 has this problem
  • Last reply by sfhowes

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I converted fro 32 bit to 64 bit Thunderbird client. The reason I did was a Windows 10 MAPI problem, but that is another issue.

The problem I am chasing... Originally I had a new computer with Windows 10 pre-installed. I installed Thunderbird about a year ago. I don't recall the version. I updated every time there was an update. I am trying to fix a MAPI problem and I thought upgrading to the 64 bit version might do the job. I Uninstalled Thunderbird 78.7.1 (32 bit). I installed Thunderbird 78.7.1 (64 bit). In chasing the MAPI problem I was told that:

  Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Clients\Mail\Mozilla Thunderbird\DLLPath 
  had to point to the correct MAPI handler.

In my case it points to:

  C:\Program Files\Mozilla Thunderbird\mozMapi32_InUse.dll

It points to the 32 bit version.

Is this an issue?

Any help will be greatly appreciated.


All Replies (3)

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I would say if anything upgrading to 64 bit will exacerbate any problems. But I really have had Zero luck using it on my own devices. It does appear you need the same "bitness" of both the calling app and Thunderbird. But that is only what I have read.

There are some bug that might be worth your time to look at.

I suggest looking at the last one first then the second last.


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Chasing the bug reports and the dialog gave me some ideas, however I still can't solve the underlying problem - Quickbooks can't find Thunderbird under Windows 10 to send my invoices.

I don't know if the apparent registry incompatibility is causing an issue. There is just not enough information to chase it down. Unlike the days of yore when there were manuals and such, getting to the root of such an issue today if you are not part of the development group is nigh on to impossible. It used to be I could contact IBM and pay for some help. If it was their bug --- no charge. If it was my problem I paid dearly - but the problem was solved.

//rant: ON Microsoft, Intuit and Thunderbird rely on feedback from users and citizens to solve their problems, not dedicated support for the money you pay for the product, except Thunderbird. Windows 10 is, in my opinion, complex beyond usefulness, and nought but a vehicle to sell stuff including user data. Intuit just doesn't have the tools or capability to isolate the problem. And Thunderbird is a free so funds for real support are limited. Me, I could fix it if I had the info on the MAPI support from end to end. //rant:OFF

Matt, I thank you for your response. Much appreciated.



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If Quickbooks is 32-bit, TB must be 32-bit in order to send emails from QB. Remove TB 64-bit, install the 32-bit version, restart the computer:


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