- Log in to your account at https://panel.dreamhost.com/.
- Click Mail on the left side and select Custom MX / Gmail from the drop-down menu.
- Click Edit next to the domain you will be using with Google Apps.
- Click I'm ready to use Gmail now!
Be aware it may take as long as 72 hours before DNS changes are propagated, depending on the time to live (TTL) that was configured for your records. Until records have been updated worldwide, you will still receive traffic to your old server.
Follow the steps within Troubleshoot MX records to fix your DNS setup.