are you using a 32 or 64 bit windows?

In help menu > about for Thunderbird does it show as 64 or 32 bit.

Yes, there were some changes in MAPI.

If the external application now sends e-mail without dialogue, it appears that the external application should set a flag to request that dialogue, see:

https://bugzilla.mozilla.org/show_bug.cgi?id=1530950#c8 and one above.

We're looking into it.

We have some reports that re-installing 60.5.2 after an auto-update works: https://www.thunderbird.net/en-US/thunderbird/all/

Personally I had to uninstall an unused version of Office to get it to work.

Thanks! Reinstalling the program from that link worked!

Details for a fix/workaround can be found here: https://bugzilla.mozilla.org/show_bug.cgi?id=1530820#c30

Basically Thunderbird need to be properly reinstalled.

Sending files with non-ASCII names may not work. There are two workarounds: Either switch the system code page to UTF-8 (if on Windows 10) or reset HKLM\SOFTWARE\Clients\Mail\Mozilla Thunderbird - SupportUTF8 to 0

Jorg K said

We have some reports that re-installing 60.5.2 after an auto-update works: https://www.thunderbird.net/en-US/thunderbird/all/ Personally I had to uninstall an unused version of Office to get it to work.

This Solution works

That worked for me, thanks.

thank you. this solution worked on a laptop and a Surface Go.

skiellerman said

Jorg K said

We have some reports that re-installing 60.5.2 after an auto-update works: https://www.thunderbird.net/en-US/thunderbird/all/ Personally I had to uninstall an unused version of Office to get it to work.

This Solution works

That did it for me. I thought I was going nuts. Then I found it was sending everything to my bcc. Thanks for the fix.