NEW YORK Email invitations may not have quite the tactile flourish of a traditional paper invitation. But using an online service like Evite.com can make sending invites and tracking RSVPs a lot easier (and cheaper, of course). Here's how it works: Evite.com makes custom-designed email invitations for your event. You give the company your guest list (with email addresses), and Evite mails them. To RSVP, guests click from the email to a special area of Evite's site, which keeps track of the responses, so you don't have to. Pricing for a custom-designed invitation and tracking starts at $2,000.