Evite may have been the first to market with online invitations, but plenty of other services have followed suit with gorgeous templates and customization options to create the online save the date or wedding invitation of your dreams. Try Paperless Post, Glo, or Riley & Grey. Most options allow you to send an invitation and field RSVPs without a single stamp. Even if you send paper invitations, cut down on costs by asking guests to RSVP by email or on a password-protected website.
Source: Riley & Grey