I installed Claws mail application and the issue was very similar. So, Evolution, Thunderbird and Claws shows the same symptoms. Fortunately, Claws first suggests a command to run when opening an attachment
xdg-open '%s'
following the command opens the Open with... dialogue box. So, I could proceed with debugging.
Funny enough, running the same command to the saved file
xdg-open filename.doc
opens the OpenOffice application with the file right away.
The Claws mail says that the attachment is filename.doc (application/msword, 56.10KiB). So, I could find out that
xdg-mime query default application/msword
ouputs org.onlyoffice.desktopeditors.desktop, but the org.onlyoffice.desktopeditors.desktop file does not exists on my filesystem.
Creating one at ~/.local/share/applications/org.onlyoffice.desktopeditors.desktop with
[Desktop Entry]
Name=ONLYOFFICE Desktop Editors
Comment=Edit Documents, Spreadsheets, and Presentations
Exec=/usr/bin/desktopeditors %U
Icon=onlyoffice
Terminal=false
Type=Application
Categories=Office;WordProcessor;Spreadsheet;Presentation;Viewer;TextEditor;
MimeType=application/vnd.openxmlformats-officedocument.wordprocessingml.document;application/msword;application/vnd.openxmlformats-officedocument.spreadsheetml.sheet;application/vnd.ms-excel;application/vnd.openxmlformats-officedocument.presentationml.presentation;application/vnd.ms-powerpoint;text/plain;
helped and the attachment is now open directly with no Open with... dialogue box. But it seems that any other .desktop files are missing. I do not want to regenerate them all manually. Is there a way to generate all or any missing .desktop files automatically?