User can't access UNC links but can browse to the same location manually, file:// syntax seems to be breaking it

I have a user that gets a UNC internal server link emailed to them and gets a file cannot be found error. The user has permissions for this folder and can access it by browsing and links work to the parent folder. Outlook is making the links using the file:// syntax and under the user's account if I go to the run window and put the unc as \\server\share\sub it will open. However if I use file://server/share/sub it will give the error. Linking by the parent folder file://server/share works. As a domain admin both forms of the link work fine for my account. This is a DFS share and I've checked and reset the user's permissions on the folder but to no use, any help appreciated.