Question 2

Suppose you need to send one message to three different users:
us...@example.com, us...@example.com and us...@example.com. Is there any difference between sending one separate message per user and sending only one message with multiple (three) recipients? Explain.

There is not much difference between sending one message to multiple users and sending one separate message per user. Most of the effects come on the sender’s side.

While sending a message to multiple recipients, the message is first sent to the outgoing email server. The email server then makes a copy for each recipient and forwards them to corresponding domain. Since there are multiple recipients of same message, the server has to send them at the same time. In this case, the usage of processor of the server is higher than usual, but there is benefit of saving disc space because the server keeps only one copy of the message.

On the other hand, while sending separate message per user, there is no pressure on email server. The server forwards the message as it receives from the sender. But the disadvantage is that the messages with different email addresses have to be saved on the server even if the message is same.