Can you lock the sorting order in Mail? (OSX 10.11) Just wondering if it's possible to lock the sorting order in Mail? My mom keeps accidentally clicking on the top bars "From, Date, Subject" and getting confused. I'd like to be able to lock it to only sort by date Descending but still display the "From, Date and Subject" tabs so she knows what she's looking at.
There doesn't appear to be an easy way to do this, so I wrote a Mail plugin for it. You can download it here, and the source code is available here. I wrote it for macOS Sierra, so if it doesn't work on your mom's computer please let me know.

To use it:
1. Open Mail and select the tab you want to lock.
2. Close Mail.
3. Copy the .mailbundle file to ~/Library/Mail/Bundles.
4. Reopen Mail. The header should now reject clicks.
5. To uninstall, remove ~/Library/Mail/Bundles/MailHeaderLock.mailbundle and restart Mail (and to change the tab, move the plugin to somewhere else, and follow these steps again).