This weekend I had to install an Apple update, which seems to have updated the Mail.app.
This new update caused the WideMail plugin not to work anymore (and so it got disabled). Normally this shouldn’t cause any problems, unless the software the poorly written. So the next time I’ve started the Mail.app, the Subject column was missing. I couldn’t even enable it anymore in View -> Columns.
After the browsing the Internet a little bit, I have found this solution:
- Exit Mail.app
- In Terminal.app enter the command:
- Start Mail.app
defaults delete com.apple.mail TableColumns
Now you should see the Subject column again, although it is still missing from View -> Columns.
You could of course also install the updated version of WideMail…