Google chrome is showing that my page uses some assets which are from the non secure source. Nevertheless its not. I can not for that existence of me understand why this really is happening. I have undergone all of the code to ascertain if there's anything getting known as from the non secure page but I wasn't capable of finding anything. I've also used the next code inshtaccess:

RewriteCond %{SERVER_PORT} !^443$
RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI} [R,L]

The url under consideration is https://app.emailsmsmarketing.com/. Any assistance will greatly be appreciated.

Check you don't have third-party inclusions, for example icons from facebook, google statistics code, AddThis buttons etc. Some icons can load something dynamically via HTTP. See my similar question which will possibly enable you to identify the issue.