Re: [exim] DKIM signing for multiple domains

On Tuesday, 25 September 2018 10:28:42 AM AEST Odhiambo Washington via Exim-users
wrote:
> Hi everyone,
>
> I have multiple domains hosted on the same server. They are virtual
> domains. The server has just one IP address and one Exim instance.
> I am wondering how to easily do DKIM signing for these domains. I decided
> to use the same selector for all the domains to make life easy. Would the
> following transport work? If not, what is the best way to do this for
> multiple domains sharing the same IP address?
>
> remote_smtp_DK:
> driver = smtp
> dkim_domain = ${sender_address_domain}
> dkim_selector = csl
> dkim_private_key =
> "/etc/pki/tls/dk/${sender_address_domain}-dkim.priv.key"
> dkim_canon = relaxed
> dkim_strict = true
I use dkim_domain = ${filter{${map{${addresses:$h_from:}}{${domain:$item}}}}
{match_domain{$item}{+local_domains}}}
which will match any addresses in a from field that are local, in addition if dkim_domain is a
list it will sign with multiple signatures (e.g. From: <user1@local1>, <user2@local2>,
<user3@remote> will add dkim signature for local1 and local2 domains.