How do I configure email notifications of Subversion commits in SourceForge 4.x?

For SourceForge release 4.x, email notifications are not available via the web UI, and will require extra commit hook scripts to be installed.

To implement commit email notifications on SourceForge 4.x, you must install extra commit hook scripts in the repository. For detailed information see the online Subversion documentation: Hook Scripts.

Note: This feature has been implemented in SourceForge 5.x. In the current release, a user can monitor a repository, much the same way they monitor a tracker for discussion forum.
Related information
Version Control with Subversion - Hook Scripts
How can I stay informed about events on my SourceForge site?