As sending emails is actually accomplished by the mail app on your phone (CamScanner only delivers the file to that app), please check out your mail app first.

If the email is sent out, it should be in "sent"; if not, it is in "outbox", then please try to share it via email again. Also, you can try to reconfigure your email account. Maybe the authorization got expired.

Please note that if the PDF size is larger than 20MB or the phone memory is not enough, it will also cause the delivery problem.

If you see the email is "sent" but the recipient never receives it, please ask her/him to check out the "Trash" or "Spam" folder first.

If the PDF/JPG/ZIP file is not attached, please try to use another mail app and see if it works.