[Pkg-exim4-users] Setting per-destination HELO values

[Sven Hartge]

Adam Nielsen <a.nielsen at shikadi.net> wrote:

> I'm migrating a server from Gentoo to Debian and need a bit of help
> with the Debian split-config system.

> The server is a mail hub, so mail goes in and out on a number of
> different network interfaces, each with a different IP and hostname.
> By default the server's hostname is sent as the HELO value on all
> interfaces, but the hostname only matches one of the IPs - on all the
> others the mismatch between IP and HELO value triggers various spam
> filters.

> Under Gentoo I had solved this by defining a different Exim
> remote_smtp transport for each IP and set the HELO value there, but as
> I am switching to Debian I would like to make use of the existing
> configuration system.  However I can only see the
> REMOTE_SMTP_HELO_DATA variable which sets the HELO value globally, and
> REMOTE_SMTP_HELO_FROM_DNS which I can't find any documentation for but
> doesn't seem to do what I want anyway.

> I am using the hubbed_hosts file to configure routing rules (which
> mail domains are forwarded to which hosts) so this would be the ideal
> place to specify the HELO name to use for each connection, but it
> doesn't look like there's anything in place for this.

> Does anyone know if what I am trying to do is possible with the Debian
> Exim configuration system, or will I need to copy across the custom
> transports I was using under Gentoo?

As far as I see this is not possible with the default Debian Exim config
system.

But I also think you don't need more than one custom transport. I use
the following one for a setup quite like yours:

remote_smtp:
  driver = smtp
  helo_data = ${lookup dnsdb{ptr=$sending_ip_address}{$value}{$primary_hostname}}

This will set the HELO/EHLO value according the the hostname of the
sending IP or to the primary_hostname, if the lookup fails.

Grüße,
Sven.

-- 
Sig lost. Core dumped.