[exim] Deny crappy HELO (fwd)

Wakko Warner writes:

> I'm not actually using the regexp above on my servers, yet. Since I am the
> sole user of the domain I have no problems blocking that. I want to be more
> strict on HELO checks, but I do not want to be as strict as verify=helo

This is the approach I use:

drop    condition     = ${if match{$sender_helo_name} 
{\N^[^.].*\.[^.]+$\N}{no}{yes}}
       message       = HELO Violation 

drop    condition     = ${lookup 
{${lc:$sender_helo_name}}lsearch{/usr/exim/MyIP}{yes}{no}}
       condition     = ${lookup 
{${lc:$sender_host_address}}lsearch{/usr/exim/MyIP}{no}{yes}}
       message       = HELO Violation 

drop    condition     = ${lookup 
{${lc:$sender_address_domain}}lsearch{/usr/exim/MyIP}{yes}{no}}
       condition     = ${lookup 
{${lc:$sender_host_address}}lsearch{/usr/exim/MyIP}{no}{yes}}
       message       = HELO Violation 

drop    condition     = ${if isip {$sender_helo_name}{true}{false}}
       message       = HELO Violation 

the MyIP file is a list of your IP addresses and domain names.

Hope that helps.


##> http://tanaya.net/vmw/
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