Spam blocking is normally done at the server. A phone would be pressed to the limit to run a good Bayesian filter, while a server is loafing with a great one. (Remember, spam doesn't come with a "this is spam" notice. The "blocking feature" has to analyze the source email address, the subject and the content to determine if it's spam or not. And what's spam to you may be something I want to get daily. One size doesn't fit all, it doesn't even fit into most phones. (My Note 3, an "older version of" a galaxy, had no such filter. Some email apps may have a kinda-sorta spam filter, but none of them can compare to running POPFile for 6 months. After that, with hundreds of emails a day, I'd see maybe one spam email a month, if that many. [A Bayesian filter has to be "trained" over a few thousand emails at least.] Unfortunately, unless you want to develop one yourself, there's no Android version [but the source is available].)