How to properly register multiple DKIMs?

Question

Domain Name System

How to correctly register several DKIM records in DNS records?
Now dkim is registered (none - some kind of domain):

v=spf1 a:mail.none.ru -all
none._domainkey		v=DKIM1; p=%%%%%%%%%
_adsp._domainkey	dkim=unknown
_domainkey		o=~

But now we want to send mailings from the spam.none.ru SMTP server, with a different IP. Do we
just add a similar record or just a public key?

Answer 1

mail._domainkey.domain.ltd = "v=DKIM1...."
mail2._domainkey.domain.ltd = "v=DKIM1...."
In the milter on the server, specify which public key to use
SPF has little to do with it .

Answer 2

Make one more txt record in dns on spam.none.ru and sign keys on this server on its behalf.