We have a domain and a subdomain which were added to Cloudflare a year ago and were working fine. Today we wanted to setup a webmail inbox on the subdomain for the first time. So we logged into Plesk and created the inbox, then added the following DNS records:
MX: eu.domain.com > mail.eu.domain.com
A: mail.eu > Plesk IP
CNAME: eu.domain.com > domain.com
But when we navigate to the webmail URL (roundcube) it says DNS_PROBE_FINISHED_NXDOMAIN. A free NS record checker site also says no NS records found. But that doesn’t make sense our website hosted on the main domain loads fine.
What could be the problem?