I'd not think of it as a "counter requirement". It's a logical
consequence of the fact that in an internet no one can control
both sides of the connection, neitther sending nor receiving.
In short, it is a truism that the sender cannot control how
the recipient processes the message in an internet.
Paul Hoffman / IMC wrote:
"The sender should be able to suggest the processing for a
particular message."
But a counter-requirement is:
"The recipient must be able to fully control the processing of
messages received."