I have set up two MX records to different servers for survivability. However, I can’t figure out how to set establish RSA public keys for both via a DKIM record. I have tried two different prefixes to the _domainkey record (like default._domainkey. and alternate._domainkey., with one ask v=DKIM1 and the other v=DKIM2) but the first one listed passes verification and the second entry fails verification.
This is beyond the scope of Cloudflare services. While Cloudflare provides DNS, the actual configuration of DNS TXT records for mail services is up to the mail host. For that, you’ll have to contact the mail host for support. If you are the mail host, then your best bet is to ask on serverfault.com or stackoverflow.com
Thank you. Will do!