I think this will be useful but
do have a few comments.
On the security points, issues
with smtp or ftp based solutions might be discussed in a comparison (are you
considering a pull case using smtp push and pop pull?) (maybe also a contrast
with HTTP GET rest solution also?) But is it really a security contrast? Spam
is a nuisance and a waste of resources etc but to be a security threat it needs
to be more than spam (or is interference or denial of service the security
point?)
Also since we did spend some
time on the “message store/queue” authorization problem, and it has been of
interest to end user review communities, I think you need to point out how the
messages for a SMB/SME company cannot be “pulled” down by “a bad (external) guy”
The 3rd party
infrastructure point (message store in a VAN flavor) is probably worth
mentioning. But is it really a security point?
(the slide from eTG deck was
too much focused on the Pull mechanism, not its rationale)