Add Axigen

Axigen is good free mail server for small environments, I use this solution when I can't use Zimbra when I don't have much hardware resources.

non-free.md

@@ -40,6 +40,8 @@
   * [ArtVenue](http://codecanyon.net/item/artvenue-image-sharing-community-script/5771542) - `⊘ Proprietary` Start your own photography community website, platform based on the Laravel PHP Framework. ([Demo](http://codecanyon.net/item/artvenue-image-sharing-community-script/full_screen_preview/5771542)) `PHP`
   * [Single File PHP Gallery](http://sye.dk/sfpg/) - `⊘ Proprietary` is a web gallery in one single PHP file. `PHP` 
 
+## Self-hosting Solutions
+  * [Axigen](https://www.axigen.com/mail-server/free/) - `⊘ Proprietary` Great alternative to open source. It's a turnkey messaging solution, perfect for small & micro businesses, integration projects or test environments.
 
 ## Software Developement