Folks,
I normally recommend backing up the entire mail folder (~/library/mail), when you need to backup your Apple Mail… Â But what if you want to share your junk mail filter data to another computer? Â For example, your significant other’s computer…
Copy the ~/library/mail/LSMMap2 file to the other computer, but don’t yet put it into Apple Mail. Â Make sure that the Apple Mail preferences are set to turn on Junk filtering (automatic), and then quit Apple Mail. Â Place the new LSMMAP2 file into ~/Library/Mail, and ensure that the file is set to read/write for the new user and that the new user is the owner as well… Â (Highlight file -> Get Info -> Permissions)
Once that is done, you should now be able to start Apple Mail, and the junk filter should be populated with the data you just moved or copied over.