I have domain.tld and want that mail.domain.tld would redirect to email.otherdomain.tld. What I have done so far: * I created CNAME record mail.domain.tld which pointed to email.otherdomain.tld. Result: SSL warning when visiting mail.domain.tld (Warning: Potential Security Risk Ahead) * I created alias domain with redirect to email.otherdomain.tld. Result: SSL warning when visiting mail.domain.tld (Warning: Potential Security Risk Ahead) * I created "Auto sudomain: *." for domain.tld and added alias. Result: SSL warning when visiting mail.domain.tld (Warning: Potential Security Risk Ahead) What should I do to properly set subdomain redirect to email.otherdomain.tld without SSL warning?
You mixed up a few things here. A CNAME is a DNS record that's not related to SSL or redirections. Using a CNAME is not a redirect, its just means that the IP of the A-Record of the target is returned when you query it in DNS. Check for which domain the certificate is issues for. This can not work for LE.