It looks to me like the function of the ```self.user_id``` variable was to cache the result, since it won't change during the course of this operation.  Replacing all uses of ```self.user_id``` with calls to ```#get_user_id_from_email``` mean that we're sending redundant queries over the wire to Yesmail.  While this probably won't get us shut down or anything, why would we rip out useful caching code?