When it comes to RSVPs, you have two main options to choose from. You can include an RSVP pre stamped card in the invitation, this is the more traditional way to do your invites. A more modern option is to ask guests to RSVP by email.
Make sure to include an "RSVP by" date. After that, if your guests haven't responded, you can reach out and let them know you need an answer. Most guests who truly want to be at your wedding will reply within the first two weeks of receiving the invitation. Providing both email and snail mail as options will help since some folks are more inclined to respond via email as soon as they receive it.
Invitations by Soirees & Showers Stationery