Will my guests need to 'sign up' to submit their RSVP?

Nope. Not at RSVPify. Never. 

Your guests can proceed with their RSVP immediately. No sign up and no hassle. 

Guest's email addresses are used for the sole purpose of sending email confirmations, and we’ll never sell, distribute or otherwise use your guest's email address for marketing purposes.

We don't do that kind of thing here at RSVPify.