Hmm, you get emails from Mozilla, or emails from others?
Usually whatever spam filters are used by your email site work the same regardless of your browser or browser version because they are applied to your mailbox on the server.
My emails are with Gmail, but there must be some connection as the Spam emails only arrive when Firefox has an update available. I have had weeks of no Spam and then a couple of days ago I started getting notifications that there is an update available which I dismissed several times because it wasn't convenient and, wham, now heaps of spam. This has happened numerous times in the past. Any advice on how my spam filters should be set up would be greatly appreciated.