why email sent to multiple people is multiple unicast not multicast

Question

I was reading about computer networks and came to know about multicasting and multiple unicast. Also read somewhere that when somebody sends an email to multiple people its multiple unicast not multicast. why so?

Thanks

Answer 1

Multicast involves a subscription from the receiver's side.

Multiple unicast is a decision from the sender's side.

The mailing list concept, although involving a subscription from the receiver's side, still is a multiple unicast: the sender being the delegate that maintains the list.