So that the Community can help you better, please tell us which Canon printer model you're using. It would also help us to know exactly which operating system is running on your computer (i.e. Windows or macOS, and which version thereof) and which application you're using to scan. That, and any other details you'd like to give will help the Community better understand your issue!
If this is a time-sensitive matter, click HERE search our knowledge base or find additional support options HERE.
Thanks and have a great day!
Before you can use scan to email, you will need to log into the the MF642 and enter your email information. You can log into the scanner and enter your information using the steps in the link HERE. For assistance with setting up your email, you can contact our support team at 1-800-652-2666. Our agents would be happy to assist.