Delivery time expiration

[Scot L. Harris]

On Mon, 2006-02-13 at 18:02 -0500, David Cary Hart wrote:

> Come on. That's hyperbole in support of a concept. I have no problem
> with greylisting unfiltered roll accounts (eg postmaster and abuse).
> 

You mean you can guarantee that every single email in and out of your
system is delivered and the recipient reads them?  

> However, the actual delay varies depending upon the cycle of the
> retransmit timing and the greylist timing. It is often necessary to
> re-transmit 451s several times which means that the recipient server
> and the SMTP are both consuming cycles and bandwidth.
> 

Agreed, the delay time varies, primarily dependent on the senders
server.  The amount of bandwidth is minimal since just the connection
dialog is involved.  I am sure much more time and effort and bandwidth
is used if all messages are processed fully.  The amount of spam
messages usually dwarfs legitimate email by a couple of factors.
 
> Furthermore, while the administrator of the recipient server might
> embrace the notion that email is not - and should not be - regarded
> as spontaneous, the average business sender is not thus inclined. He
> or she expects that his or her transmission will be read immediately
> in many cases.
> 

That is the perception problem mentioned previously.  The basic system
of email works remarkably well.  Except for the spam issues.

Spontaneous is probably not the right term.  Instantaneous is the issue.
If you want instantaneous an IM solution is a better solution.  Or a
phone call.
 
> Taking it a step further, many business emails are group discussions
> with several recipients necessitating spontaneity. If one recipient
> has the bad luck to be on a greylisted server, it affects the group.

I would not call being on a server using greylisting bad luck.  :)

If communicating in a group is time critical email is just a poor
choice.  There are several other options that are better for such
communications.  

But there are other tools that can be used to fight spam if you don't
like greylisting.  No one is forcing it on you.  

In my experience it has been an excellent tool with no real downside.
After watching a system with spamassassin almost melt down during
several spam storms, greylisting solved that problem.  Resources used by
spamassassin dropped by several magnitudes since few messages had to be
processed by it.  Greylisting successfully blocked the bulk of the spam.
The few spam messages that get past greylisting are typically caught by
spamassassin.  

If you have not tried it you might want to.  The results far exceeded my
expectations.