Often when receiving this error, the cause is due to the email address you're sending from not existing, or that you're logged into webmail with the primary cPanel username. The correct procedure is to access webmail or your mail clients using a full email address and related password.

To correct this, you can create an email account beneath the "Email accounts" section within cPanel and use that to access your mail in the future.

If you've already created an email address and need to reset the password, it's available beneath "Email Accounts" under the Change Password dropdown next to the email address within cPanel.

Don't hesitate to contact our support team if you have any questions.