This question is asked a lot, and it is weird that Google Calendar doesn’t allow for this, given you can add alternate email addresses to your calendar. If you want the RSVP to come from your alternate email then you need to respond directly from that email, not from the main or default email.
This guide gives you three quick ways to get in touch through Google Calendar, with your guests on web or mobile.
Update September 2020: Google is slowly rolling out the ability to add Tasks from the Google Calendar mobile app which is fantastic news. When you click on the + button in the bottom right, you’ll see the ability to add a Task as well as Event or Reminder. No more worrying about where your tasks […]