Yet still, without a webmail client (a client that specifically takes an offline protocol and puts it on the “web”) email would not have a URI. You an “link” to

Yet still, without a webmail client (a client that specifically takes an offline protocol and puts it on the “web”) email would not have a URI. You an “link” to a mailbox, but not create a particular mail with a particular identifier then later retrieve it with that same URI. The URI identifies the users mailbox, NOT their mail.