Author: Alan J. Flavell Date: To: Exim Users List Subject: Re: [Exim] exim HELO ack
> On Wed, Aug 27, 2003 at 05:34:28PM +0100, Jez Hancock wrote:
> > Is it not even more expedient to drop bad HELO/EHLOs in an acl_smtp_helo
> > ACL or is this potentially problematic?
It *can* be problematic: some misguided but otherwise bona fide hosts
treat rejection at HELO time as retryable.
If you want to be rid of them, wait till RCPT time, and hit them on
the head at that point for the bad HELO. What's more, you'll get more
indication in the log as to what was going on, which can be useful
when questions come up. That's what we do with illegal characters in
the HELO (quite a few Koreans trying to HELO with incomprehensible
strings of bytes, for example...).
Some idiot MTA software will then ignore your carefully crafted
rejection message, and tell the would-be sender that the recipient
doesn't exist - but that's not your problem.
