Load Balancing with Postfix [and SpamAssassin]
Ross Werner
ross at agilestudios.com
Fri Jan 20 16:58:14 MST 2006
On Fri, 20 Jan 2006, Michael L Torrie wrote:
> No IP is not "best effort." TCP/IP is, though.
I think either you or I is confused as to what "best effort" is.
As far as I can tell, "best effort protocols" are ones in which no
guarantees are made as to whether the data has been delivered or not.
I've googled and googled and everything I see lists IP as a best-effort
protocol, and TCP/IP as providing guaranteed services.
http://en.wikipedia.org/wiki/Best_effort_delivery
http://en.wikipedia.org/wiki/TCP/IP#The_transport_layer
http://www.bellevuelinux.org/best_effort.html
http://www.erg.abdn.ac.uk/users/gorry/course/arq-pages/best-effort.html
> I understand your point, however. And I counter it by saying that the
> very problems that gray listing is striving to counter already cause
> these types of problems. For example, spam and spam scanning already
> cause large organizations to have slow e- mail delivery.
Well, sure, if greylisting causes a slowdown in email delivery speed but a
net increase in email delivery speed then obviously that gets rid of one
of the bad points of greylisting. I certainly can agree with that.
I was only addressing the attitude of "SMTP was never designed to be an
instant form of communication, it was never intended to be reliable, it's
simply a best-effort system, so it doesn't make any sense when Joe Q. User
complains that greylisting slows down his email delivery speeds."
Sounds like we may be in agreement :)
~ Ross
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