dkim selector linux display - SERP Analysis

https://serverfault.com/questions/1110491/how-destination-mail-server-can-know-the-dkim-selector

https://blog.warmy.io/blog/dkim-selectors-step-by-step-guide-on-how-to-find-dkim-selectors/

https://powerdmarc.com/how-to-find-dkim-selector/

https://dmarcian.com/dkim-selectors/

https://www.linuxquestions.org/questions/linux-server-73/dkim-no-selectors-detected-4175730401/

https://easydmarc.com/tools/dkim-lookup

https://mxtoolbox.com/dkim.aspx

https://www.cisco.com/c/en/us/support/docs/security/secure-email-gateway/217073-how-to-use-dig-nslookup-to-find-spf-dki.html

https://linuxincluded.com/testing-spf-dkim-and-dmarc/

https://docs-ospc.rackspace.com/support/how-to/cloud-dns/create-a-dkim-txt-record/