You CANNOT use a referral link in an email.

This statement is false because you absolutely can use a referral link in an email. Many businesses and affiliate programs encourage or even rely on email marketing to distribute referral links to their audience. This allows recipients to click the link directly from the email to make a purchase or sign up, attributing the referral correctly. There are no technical or general policy restrictions preventing the inclusion of referral links in emails. The "True" option is incorrect because it implies a non-existent limitation.