How do I reuse DKIM private and public key in Virtualmin?

[calport]

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Use same DKIM in 2 different VPS

It is possible, in theory. I have never done exactly this though when migrating servers, I have applied the private key from old server to new server so that the old DKIM DNS records work across the migration. Take the private key from one server and apply it to the other server. On Virtualmin systems they are in /etc. The filename is dkim.key or something equally obscure.