I have successfully added Let's Encrypt SSL certificate for my Sever Hostname/FQDN but the issue is that When I am logging on my Roundcube mail , The messages is not showing on a same Frame.      Open the file  # vi /usr/local/apache/conf.d/ssl.conf  Header always set X-Frame-Options DENY   and can be changed to   # vi /usr/local/apache/conf.d/ssl.conf  Header always set X-Frame-Options SAMEASORIGIN  Now login to your webmail and check . 
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