verifying gpg signature under opendkim-lua script

[Robert J. Hansen]

> This is a very uncommon situation. I am running some news-letter mailing
> under postfix mail server [yw-0919.doraji.xyz; Ubuntu 18.04.6 LTS]
> (Google Cloud's Compute Engine). That news-letter email is sent
> automatically every day by cron. And that email be signed with gpg
> signature in start time (ed25519;
> 0x031016E4BEA9EA6A3A0F7D4DF60CC059E52D9596; made by GnuPG 2.2.4).
> 
> And outbond's mail server [yw-1204.doraji.xyz; Debian 11 (Bullseye)] has
> OpenDKIM filter (with lua script). If possible, i would like to verify
> the gpg fingerprint of that email with this OpenDKIM lua script. *This
> point is my real question.*

I've been holding off on this in the hopes someone better at Lua 
scripting than I would speak up, but apparently I'm what you get.

My first question is, "what are you hoping to achieve by verifying the 
fingerprint?" Do you actually mean verifying the digital signature on 
the email?