This plugin is for signing all outbound emails with an S/MIME certificate.
It uses phpmailer to automatically sign emails. Here are the prerequisites to use this plugin: * This plugin is for single-user WordPress site, such as a personal blog. I don’t know what will happen if you put it in a multi-user site. * PHP 8.3 and above are recommended. Make sure your PHP has openssl extension, which is usually installed by default. * You should use another plugin, such as FluentSMTP, to send emails through an external SMTP server.