I am currently using this in my htaccess:
RewriteEngine On
RewriteCond %{HTTP_HOST} ^example.com [NC]
RewriteRule ^(.*)$ https://www.example.com/$1 [L,R=301]
RewriteCond %{HTTPS} !=on
RewriteRule ^ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]
But it has the unfortunate effect of redirecting every call to the mobile site (m.example.com) to the main page. How do I make an exception to m.example.com? I don't know how to setup RewriteRule correctly.