On 28/10/2019 21:49, Christian K via Exim-users wrote: > I’m trying to sign all mails with DKIM from all subdomains of certain
> domains with the key of the „main“ dkim domain. Or in other words I
> want to find the dkim fallback domain to know which key I need to use
> for signing.
>
> Some examples for what domains I need to find the key for:
> foo.example.com -> example.com
> foo.bar.example.com -> example.com
> foo.example.co.uk -> example.co.uk
> foo.bar.example.co.uk -> example.co.uk
>
> I thought about using some regex substitution but with double domains
> it’s not that’s easy.
>
> Is there another way to achieve this?
Presumably you have a list of all your domains.
It's a simple lookup, then. Just write a suitable
file, or database, and use that.
--
Cheers,
Jeremy
