what is the best practice for setting up an valid STARTSSL, SSL, Certificate?
the Server/Webmin URL is server.domain1.tld
mail.domain2tld, mail.domain3tld resolves to server.domain.tld. I added all Maildomains to the ssl Cert request at server.domain.tld.
But https://de.ssl-tools.net/mailservers says only the Cert for server.domain.tld is valid. but not the mail domains from the other domains. The Email Clients have problems with it.
Any idea? Maybe an CNAME Record is better to server.domain.tld?