I installed ispconfig a few days ago. The server is server1.perelon.com.br. On this server I have 2 domains: perelon.com.br and aprendacomjogos.com.br. Today I installed Letsencrypt certificates, first on aprendacomjogos.com.br and then perelon.com.br. When requestinf the certificates I request certificates for the sub domains (using the -d flag) www and mail for each of the certificates. The certificates work fine for the websites ( that is, they go directly to https:// without any errors or problems). My problem is with email. I use Thunderbird and when I try to create an email account, when I change the POP3 port from 110 to 995, I get an error message that Thunderbird can't fine the configuration for this email account. If I change the port back to 110, the error goes away. What do I need to do to secure the email?