Final answer:
Pressing the Ctrl key and clicking an email hyperlink opens a new window for composing an email to the linked address in the default email client or browser.
Step-by-step explanation:
When a reader presses the Ctrl key and clicks on an email hyperlink, typically, a new window or tab will open in their default web browser or email client, directed to the email compose page with the hyperlink's email address prepopulated in the recipient field. This action is a shortcut to quickly writing an email to the hyperlink's specified address without having to copy and paste the email or manually typing it into the email client. The exact behavior can vary slightly based on the operating system and the default email application settings.