So we have a situation where we are utilizing another CA with a wildcard certificate on power360web.com, however, we would like talentlms to work with letsencrypt to provide wildcard ssl for all domains under the subdomain learning.power360web.com. Is this possible? Azure DNS let us know that we are unable to provide a separate CAA record for learning.power360web.com, but offered that we validate the domain using an email to an email address set up for power360web.com. Is that possible? Can you assist?
no, entire point of CAA issue is make explicit whitelist of CA that allowed to sign certificate for it, and that domain has only digicert on allowed ca list: you can add another CAA record to allow issue from LE, at main domain or required subdomain (if DNS admin allows)