Mavericks Mail will not save preferences
Solution 1:
Make sure that all the permissions are correct on your home folder.
You can use the ACL tool on the Recovery HD to do this:
- Boot into the Recovery HD using ⌘R.
- Run
resetpasswordin Terminal (available from Utilities → Terminal). - Select your account from the drop-down list.
- Click the Reset button for Reset Home Directory Permissions and ACLs.