Re: [Paddlewise] SPOT - A few observations

I saw mention of this device on another list, and discovered
that it apparently uses email to send emergency information.
Here's what I wrote:


However, I can comment on the use of email as an emergency notification
mechanism, and my comment is "very, very bad idea".

Email relies on the SMTP protocol to move around the 'net, and the SMTP
protocol is "best-effort" -- no better.  Yes, there have been scattered
efforts from time to time to craft additions that would make it more
reliable, but none of those have gained significant traction over the
past few decades, and so while in isolated environments (such as someone's
office LAN) they _might_ work, there is really no such thing as guaranteed
email delivery over the Internet, either in terms of timeliness
or even just delivery.

Moreover, mail systems are under constant, increasing, varied assault
by numerous adversaries, and these attacks often lead only to significant
delays and outages.  And on top of *that*, countermeasures deployed to
defend against these attacks often have side effects which result in
further delays and outages. (Example: some sites "graylist" incoming
mail, which means that first delivery attempts are refused, but subsequent
ones will be accepted.  If the sending site's retry interval is, let's say,
four hours, then attempt #1 at 7:54 AM will fail, and the mail message
will sit in the queue going nowhere until at least 11:54 AM.)

As I've cautioned clients, don't think of it as "mail".  Think of it
as a hastily-scribbled postcard whose contents might be read by anyone
while it's in transit, and which MIGHT eventually get where it's going.
Never, ever rely on email for communications where timeliness or
guaranteed delivery are essential -- that's what FedEx or certified mail
requiring a signature are for.

All of which means that it's completely inappropriate to use email as
an integral component of a real-time emergency notification system.
(As a supplement, sure; multiple channels are a good idea.  But not
as the primary mechanism.)

---Rsk
***************************************************************************
PaddleWise Paddling Mailing List - Any opinions or suggestions expressed
here are solely those of the writer(s). You must assume the entire
responsibility for reliance upon them. All postings copyright the author.
Submissions:     PaddleWise_at_PaddleWise.net
Subscriptions:   PaddleWise-request_at_PaddleWise.net
Website:         http://www.paddlewise.net/
***************************************************************************