How to get notified when someone pushes into a GitHub branch?

Not quite – but close enough. (You’ll get notified for every commit, not push.)

For GitHub Enterprise as of mid 2014:

1. Go into your repository’s Settings
2. Open the “Webhooks and Services” tab
3. Click “Add Service” button
4. Select “Email” from the long list of services
5. Put in an e-mail address. This can be an e-mail address that forwards to multiple e-mail addresses, or just your own if only one person/account needs e-mail notifications.
6. Check “Send From Author” (probably) and “Active” (definitely).

For older versions of GitHub Enterprise:

1. Go into your repository’s Settings
2. Open the “Service Hooks” tab
3. Select “Email” from the long list of services
4. Put in an e-mail address. This can be an e-mail address that forwards to multiple e-mail addresses, or just your own if only one person/account needs e-mail notifications.
5. Check “Send From Author” (probably) and “Active” (definitely).

Done!

Update GitHub plans on shutting down GitHub services before the end of the year. Refer