Redmine

I'm working with version v0.8.0 of redmine in a project and now we need to create the issues via email, i was reading the forum and i think this feature it's already done in RedMine but i don't know how i can enable or use this.
The only thing that i've done for the moment was enabling the "Enable WS for incoming emails" option in Settings/Incoming emails page (see image attached)
Do i need to update my files to the svn because i don't know how to do this?
I was reading the "Anonymous issue creation via email" (http://www.redmine.org/projects/redmine/repository/revisions/2789), but i don't get it how to enable this option, what i must to do, do i need to add some script in the mail configuration file (email.yml) ?
I've already read the "Receiving" emails" in the administrator guide too, i need to choose one of this option for receiving email right ?
Can you please give me an example of a simple mail configuration for creating issues via email, which one is the easiest of the 3 options.
Thanks in advance for any help