What are some alternatives?
MailScanner - MailScanner is a open source email security system design for Linux-based email gateways.
SMS Junk Filter for iOS - Block unwanted SMS spam text messages
Scrollout F1 - Scrollout is a free and easy to use anti-spam email gateway designed for Linux & Windows administrators without advanced email security experience.
SpamSieve - Save time by adding powerful spam filtering to the e-mail client on your Mac.
Mailwasher - Over 8 million people use MailWasher as their spam filter
MyHumans - Block calls from numbers not in your contacts