I have certbot installed and successfully use it to encrypt my homepage.
Now i tried to setup an email system for my website using dovecot and postfix.
I got it mostly running, only problem is, that thunderbird gives me a warning about the adress being fraudulent because I use the ssl key of mysite.com for imap.mysite.com (same for smtp) So how can I add imap.mysite.com and smtp.mysite.com to the existing mysite.com certificate using certbot in order to avoid the warning?