Re: [exim] Is this true

--On May 4, 2005 15:42:19 +0100 Ron McKeating <R.J.Mckeating@???>
wrote:

> This is a claim made by Mirapoint in a bulletin put out by UCISA, I am
> not convinced that the last paragraph is true, I thought there were
> quite a few sites that did not respond correctly to greylisting like
> this. Is this just steaming bison poo ??
>
>
> To verify the sender, MailHurdle looks at the originating IP address and
> the From and To addresses in the message. If a particular recipient
> hasnʼt previously received a message from the senderʼs IP address,
> MailHurdle sends a temporary failure message back to the originating
> mail server using a standard SMTP failure code. If the originating mail
> server is a bulk e-mail system, it will generally not resend the
> message. Viruses using raw SMTP to send messages will also not retry.
>
> If the message is legitimate, the originating mail server will quickly
> retry sending the message, at which point itʼs allowed through the
> gateway. (According to Mirapoint, thereʼs one old version of GroupWise
> that may not properly retry unless itʼs patched, but every other e-mail
> server the company has found supports this SMTP command.)

Well, it may be that all mail servers are *capable* of retrying, as the
parenthetical comment suggests. That's not the point though. The question
is how many are *configured* to retry.

>
> Ron
>
> --
> Ron McKeating
> Senior IT Services Specialist
> Computing Services
> Loughborough University
> 01509 222329



--
Ian Eiloart
Servers Team
Sussex University ITS