The opportunity and feasability of this idea has already been discussed
in 1992. I remember that some of us (including myself) faced a barrage
fire from the IETF saying :
we will never accept that because 1) faces are ugly b) it will
slow down MUAs c) it will considerably increase traffic d) do
you really think I want to see the face of the neird who sent
me a mail yesterday ?-)
points a and d are just stupid. I have been using my own faces-enabled MUA
during 5 years and nothing is more visual than a face or a logo.
points b and c are a real concern.
I have developed in 1991, as part of the Meuf package, a daemon based on
the finger daemon able to answer a picon to a request on a given port.
A call issued by a MUA, on user's request, is for me an implementable
solution. An automatic retrieval of faces for all incoming messages
is IMHO a bandwidth murder.
</Daniel>