This feature is provided by SVN by default. Go to the /repo/hooks directory and edit the post-commit with the following Ruby code, then whenever someone checks in to the SVN, an automatic email will be sent out.

Note: this script requires Ruby and sendmail (and of course, Subversion) to work correctly. The following script is adapted from two posts A better Subversion post-commit hook than commit-email.pl and Pretty SVN commit emails. The difference is that this script sends out emails to a group of members rather than one.