Re: [exim] Exim rejects: syntactically invalid argument

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.

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