Hi,

On Sat, 8 May 2004 17:31:26 +0200 Heinz Ulrich Stille <[EMAIL PROTECTED]> wrote:

> On Saturday 08 May 2004 16:12, Pat Masterson wrote:
> > Does anybody have a rule to recognize my own IP in the HELO ?
> > thanks.  -pat
> 
> It's much simpler to let the mta reject the connection outright. No chance
> that there could come something good over it.
> In postfix eg. append check_helo_acces to the smtpd_helo_restrictions with
> a cidr table containing REJECTs for your network address, and while you're
> at it, another one with your domain name(s).

For the network 66.143.181.8/29 and the domains
(austinimprov|cynistar).(com|net|org) I use the following PCRE map in
Postfix:

/66\.143\.181\.([8-9]|1[0-5])/  550 5.7.1 Do not masquerade as local server. 
Begone.
/^(austinimprov|cynistar)\.(com|net|org)$/  550 5.7.1 Do not masquerade as 
local server. Begone.
/^<?\d+\.\d+\.\d+\.\d+>?$/  450 HELO is an IP literal; try again with an actual 
resolvable hostname
/^localhost\.?/         450 Please fix your HELO to be an actual resolvable 
hostname

Caveat: my local clients and MTAs all HELO with a host name, not domain
name so it's safe to drop anything HELOing as cynistar.net, etc.

Actually, rules #1 and #3 are redundant if you consider IP literals as
HELO strings to be illegitimate; the difference is that #1 should never
FP and #3 will only FP on badly misconfigured mailers. It might catch
clients but clients should be talking to your MSA, not directly to your
MTA anyway.

hth,

-- Bob

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