Post-commit email notification

Hi, I use SVN + TortoiseSVN under Windows 7. I would like to send an email after someone do a commit in a specific repository. I know this is posible by programming a .bat and adding it as a post-commit hook scripts in the settings. The problema is that I don't know how to do that, I mean the code. Not even if it works on my computer, because I try with a simple notepad.bat in which after a commit a "Hello world" appears (by using echo "Hello world").  Could anyone help me??  Thanks in advance!  María J.