Re: [exim] Exim rejects: syntactically invalid argument

--On 29 September 2005 20:48:01 +0100 Chris Edwards <chris@???>
wrote:

> On Thu, 29 Sep 2005, Alan J. Flavell wrote:
>
>| For clarification please - is this at HELO time? When we originally
>| set ours up (admittedly some years back now), we found that rejection
>| at HELO time would provoke some offering MTAs into repeated retries -
>| in some cases, very aggressively so. I suspect "drop" would be even
>| worse...?
>|
>| So we deferred rejection until RCPT time, which seemed to be the most
>| effective way of getting them off our backs.
>
> Of course, the other reason for rejecting at RCPT time is the sender and
> recipient addresses are in the logs, which can make hunting down problems
> a little easier.

Yep, it also gives someone an opportunity to reach postmaster and ask what
the problem is!

> That said, I don't recall a single instance of genuine mail impacted by
> "our HELO" test.

We've rejected genuine mail when the HELO string included an illegal
underscore. We also check that our server's hostname isn't in the HELO
string. I'm not aware that's ever caught genuine mail.

--
Ian Eiloart
Servers Team
Sussex University ITS