Is it possible to send an invitation to one or more email addresses when creating and/or modifying an event in a format which can be added to the recipient's calendar?
Hello,
It certainly is.
In RSVP Pro we have Invitations, which allow inviting individuals or groups, auto invite is also possible.
We have recently introduced a new feature which allows sending the invitations as iCal Emails, so It can be added to their calendar.