iMIP - Introduction
iMIP is defined by RFC 6047 which defines how [iTIP] messages are sent and received via email.
Given that email is a major vector for spam and other attacks, senders and receivers must take care over the handling of iMIP.
However, iMIP is still the most interoperable way to ensure that an iTIP request reaches the owner of an email address.
Note that iMIP is also used to resolve the “identity crisis” as it’s called within calendaring. Many people have their calendar hosted on one service, but their email address hosted somewhere else. Using iMIP allows the receiver of the message to choose which calendar to use.
(Note - the documents in this area require many more examples of what iMIP messages look like in different contexts.)