George
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On Sat, 2008-01-12 at 11:27 -0800, George wrote:
> I'm using the following ACL to drop incorrect HELO names:
>
> deny condition = ${if ! match {$sender_helo_name}{\N^[^.].*\.[^.]+$\N}}
> message = "See RFC2821 section 4.1.2 for legal domain syntax"
> log_message = invalid HELO syntax 1 $sender_helo_name
Assuming your clients are using the submission port, 587, you could have
above that at the start of your HELO ACL:
accept condition = ${if eq{$received_port}{587} }
This, obviously, is a small risk in case one of your client machines
gets a trojan/worm/other malware which utilises the defined system MUA
in the background as a sending engine, but if you make your clients use
the submission port with authentication then you'd be following best
current practice *and* not then really care what HELO/EHLO the client
sends.
Graeme