Thunderbird

Changes to the MAPI interface have caused problems when sending a file from the Windows desktop or a folder via "Sent to > Mail recipient" or via an external application like an office package, for example LibreOffice. To solve this problem, reinstall Thunderbird 60.5.2 from one of these locations:
https://www.thunderbird.net/en-US/thunderbird/all/
http://ftp.mozilla.org/pub/thunderbird/releases/60.5.2/win32/
http://ftp.mozilla.org/pub/thunderbird/releases/60.5.2/win64/ (unsupported 64bit version).
Files with non-ASCII characters in their name also cause a malfunction. Two alternative workarounds exist:

On Windows 10, set the system code page to UTF-8 (beta feature, see Region Settings, system locale)
Reset this registry entry
HKLM\SOFTWARE\Clients\Mail\Mozilla Thunderbird - SupportUTF8 to 0

Thunderbird is an open source project, which means anyone can contribute ideas, designs, code, and time helping fellow users.

Thunderbird is a free email application that’s easy to set up and customize - and it’s loaded with great features!

Experience cutting edge features. Provide feedback to help refine and polish what will be in the final release.

Help us test the newest developments made to Thunderbird every day by using the unstable Daily channel.

WARNING! Daily is an unstable testing and development platform, make sure you back up important data regularly!