And a very relevant one because if you simply highlight the email to delete it, and you have a "Preview Pane" open, then that is the same as opening the email.
You don't say what you use to manage your emails, either web-access via a web page, or email software like Windows Live Mail, Thunderbird, Outlook, or similar.
I find that in Web mail I can simply tick a small box next to the suspect email, then click the Delete button in the button options above the email listing.
But I generally use Thunderbird software to manage my emails and I have the Preview Pane open, and there are no 'tick' options available. So, I turn off the Preview Pane before highlighting the email, then highlight it and delete it. Then turn the Preview Pane back on.
Does that help?
When I get a suspicious e-mail that may contain a virus, how can I delete it without the email opening when I click on it to delete it?
I am using Windows 7