Click the Exhibit button. You are composing an e-mail message. You attach a file to the e-mail message. After composing the e-mail, you press the Send button. However, Outlook 2010 prompts with the…

Click the Exhibit button. You are composing an e-mail message. You attach a file to the e-mail message. After composing the e-mail, you press the Send button. However, Outlook 2010 prompts with the error message shown in the exhibit. If you click the Yes button, Outlook will send the message. However, re cipients of the e-mail will not be able to open the attachment because it is blocked. If you click the No button, you can remove the unsafe attachment. Which of the following is a cause of the issue?