How do we keep _e-mails "closed" if we wish not to open it. E-mails seem to open whenever we click onto it, wish to move it or when it has just come in as a new email.

How do we keep incoming e-mails unopened until we decide whether or not we want to read it.  Each new e-mail is automatically displayed upon arrival,  or when clicked on, or even when moved.  What about security on an infected e-mail which opens whether we want to read it or not.  Have I missed some programming here?