Redmine

Hi there,
I've been asked to configure Redmine to allow tasks creation from mails sent by users. I've read the guide at the following link:
[[http://www.redmine.org/projects/redmine/wiki/RedmineReceivingEmails#Fetching-emails-from-an-IMAP-server]]

As you asked I let you the following informations:

ruby -v
ruby 2.1.5p273 (2014-11-13) [x86_64-linux-gnu]

rails --version
Rails 4.2.6

OS:
Windows 10 Pro (no cygwin)

Ruby-aware server used:
Webrick

What I guess I have understood up to now, is that I have to define a task (.rake file) in lib/tasks.
The first problem is that I don't know what to write inside this file (never wrote a rake task).

After having done it I want to create a crontab, and here is my second problem: where must I put it?

As you can realize by reading my post I am not really skilled, so I may have expressed my issues in a bad way: I am sorry for that.

I am sorry for my poor english too.

Thank you in advance anyway.

P.s. I have found a file at the following link:
[[https://svn.redmine.org/redmine/trunk/lib/tasks/email.rake]]

could I use it for my purpose?