Ubuntu Server24.04 ; Web server, Mail server SSL conversion (Let's Encrypt)
1. Obtain a certificate(Let's Encrypt)1.1 advance preparation1.Enable mod_ssl# a2enmod ssl2.Package management system Snappy installedLet's Encrypt's SSL certificate issuing tool "certbot" is recommended to be installed using "snap" after 2021, so install Snapd first.2. SSL/TLS (Let's Encrypt) configuration for Apache2①Edit Apache2 SSL-related configuration fileshoge.com-ssl in hoge.com-ssl.conf is an arbitrary name3. SSL/TLS (Let's Encrypt) settings on the mail server3.1 Obtaining a certificate for the mail serverObtain a certificate for the mail server, but it cannot be obtained in the same way as above, so the following with the "--standalone" option fails.